Posted on by Ken Kremer

KSC and Visitor Complex Reopen in Aftermath of Hurricane Irma; with Launches Delayed and Viewing Spots Destroyed: Gallery

Rotary Rover Front park along the Indian River lagoon in Titusville, FL which offered a magnificent view of the iconic Vehicle Assembly Building and launches from Launch Complex 39A on NASA’s Kennedy Space Center was destroyed by Hurricane Irma on Sept. 10/11, 2017. Credit: Ken Kremer/kenkremer.com
Rotary Rover Front park along the Indian River lagoon in Titusville, FL which offered a magnificent view of the iconic Vehicle Assembly Building and launches from Launch Complex 39A on NASA’s Kennedy Space Center Credit: Ken Kremer/kenkremer.com

TITUSVILLE/CAPE CANAVERAL, FL – NASA’s Kennedy Space Center, the KSC Visitor Complex and Cape Canaveral Air Force Station have reopened as of today (Sept. 16) and yesterday, respectively, in the aftermath of Cat 1 hurricane force winds from Hurricane Irma that lashed the Florida Space Coast on Saturday, Sunday and Monday (Sept. 9/10/11) – forcing launch delays and leaving damaged and destroyed homes, buildings, infrastructure and launch viewing locations in its wake – see photos.

Cape Canaveral Air Force Station military forces partially reopened certain critical runways hours after Irma swept by the space coast to assist in emergency recovery operations.

“Kennedy Space Center will resume normal operations Saturday, Sept. 16,” NASA announced. “The “All Clear” has been given to reopen.”

NASA’s world famous Vehicle Assembly Building and the Space Coast launch pads are still standing – as seen in photos from myself and more from NASA.

Launch Complex 39 and surrounding areas are seen during an aerial survey of NASA’s Kennedy Space Center in Florida on Sept. 12, 2017. The survey was performed to identify structures and facilities that may have sustained damage from Hurricane Irma as the storm passed Kennedy on Sept. 10, 2017. Credit: NASA KSC

“As you’ve all seen by now, the Center will be open for normal operations at midnight tonight, and we’ll be ready to get back into the full swing of things Monday morning,” KSC Center Director Bob Cabana said in a message to employees.

Hurricane Irma knocked out water and power to KSC, the Cape, the visitor complex and the barrier islands including Merritt Island which is home to America’s premier Spaceport.

Wind speeds at KSC “varied from 67-94 mph (59-82 knots) at the 54-foot level to 90-116 mph (79-101 knots) at the 458-foot level during the storm.”

As a direct result of Irma, the next Space Coast launches of a United Launch Alliance Atlas V and SpaceX Falcon 9 has been postponed into October.

“The storm did delay the next launches,” said Brig. Gen. Wayne R. Monteith, Commander, 45th Space Wing, at a media briefing.

“We think the next launch will be approximately the first week of October.”

However although there was damage to a numerous buildings, both the spacecraft and rockets are safe and sound.

“The spacecraft we have on station right now are healthy and are being monitored.”

“The seven rocket boosters [Atlas, Falcon, Delta IV Heavy] we have on the Cape rode out the storm just fine,” Montieth elaborated.

The base and the visitor complex both lacked potable water service used for drinking, food preparation and cleaning.

Multiple water pipes in the nearby community of Cocoa were severed. KSC, the Cape and the Visitor Center as well as the surrounding community were under a boil water restriction for several days.

“Full water service is now available and the center has received an all clear following several days of closure related to Hurricane Irma,” noted KSC officials.

Space View park along the Indian River lagoon in Titusville, FL which offered a magnificent view of the iconic Vehicle Assembly Building and launches from Launch Complex 39A on NASA’s Kennedy Space Center was destroyed by Hurricane Irma on Sept. 10/11, 2017. Credit: Ken Kremer/kenkremer.com

Indeed over 87% of customers lost power in Brevard County – home to the Florida Space Coast. Over 2/3 of customers lost power throughout Florida- impacting over 16 million people.

A number of popular public launch viewing locations were also severely damaged or destroyed as I witnessed personally driving in Titusville around just hours after Irma fled north.

See my photos from Rotary River Front Park, Space View Park and others along Rt. 1 in Titusville – which had offered unimpeded, spectacular and beautiful views across the Indian Rover lagoon to the KSC and Cape Canaveral launch pads.

Space View park along the Indian River lagoon in Titusville, FL offered a magnificent view of the iconic Vehicle Assembly Building and launches from Launch Complex 39A on NASA’s Kennedy Space Center until the piers and walkways were decimated by Hurricane Irma on Sept. 10/11, 2017. Credit: Ken Kremer/kenkremer.com

Piers, docks, walkways, parking areas, piping and more were ripped up, smashed, sunken and devastated with piles of metal, bricks, wood, trees, bushes, trash and more scattered about in sad and unrecognizable heaps.

Space View park along the Indian River lagoon in Titusville, FL offered a magnificent view of the iconic Vehicle Assembly Building and launches from Launch Complex 39A on NASA’s Kennedy Space Center until the piers and walkway were decimated by Hurricane Irma on Sept. 10/11, 2017. Credit: Ken Kremer/kenkremer.com

From a distance of several miles, the iconic VAB and the launch pads themselves did not seem to suffer obvious destruction – see my photos herein.

As of today over 500,000 customers across Florida remain without power, including tens of thousands in central Florida.

Numerous traffic lights in Titusville, Cape Canaveral, Cocoa Beach and Melbourne and other Brevard County and central Florida cities and communities are still not functioning today – creating all sorts of road traffic hazards!

Rotary Rover Front park along the Indian River lagoon in Titusville, FL was devastated by Hurricane Irma on Sept. 10/11, 2017. The serene coastal park had offered magnificent views of the iconic Vehicle Assembly Building and launches from Launch Complex 39A on NASA’s Kennedy Space Center. Credit: Ken Kremer/kenkremer.com

Damage assessment teams from NASA, ULA, SpaceX, the USAF and contractors are now carefully scrutinizing every aspect of the Space Coast launch pads and facilities to ensure successful liftoffs whenever they resume in a few weeks.

Virtually all traffic lights were not operating and businesses and gas stations were closed in the hours before and after Irma pummeled communities across the space coast and central Florida. There were very long lines at the first gas stations that did reopen on Monday and Tuesday.

NASA’s iconic Vehicle Assembly Building (VAB) and the Launch Control Center (left) were home to the ‘ride-out’ crew remaining on site at the Kennedy Space Center, FL during Hurricane Irma to monitor facilities as the storm passed by on Sept. 10/11. They survived intact in this post storm view taken from Playalinda Beach. Credit: Ken Kremer/kenkremer.com

KSC was closed and evacuated of all personnel during the storm, except for only a small ‘Ride-out’ team of roughly 130 or so KSC personnel based inside the Emergency Operations Center (EOC) inside the Launch Control Center. They remained on site to monitor spaceport facilities.

“I want to take this opportunity to thank—and commend—the Ride-out and Damage Assessment and Recovery Teams for the outstanding job they did watching over the Center in our absence and getting it ready for our return in the aftermath of Hurricane Irma,” Cabana added. “I also want to thank all of you for the outstanding job that you did in getting the Center ready for the hurricane. As a result of your efforts, the Center was well prepared for the storm.”

The Damage Assessment and Recovery Teams explained that “the industrial and Launch Complex 39 areas have been inspected and are safe for personnel to return to work. This includes the KSC Child Development Center and all administrative work areas.”

Huge slabs of coastal concrete walkway buckled and collapsed on Route 1 along the Indian River lagoon in Titusville, FL that was a popular spot offering outstanding public launch viewing – decimated as Hurricane Irma passed by on Sept. 10/11, 2017. Credit: Ken Kremer/kenkremer.com

“All facility systems including communication, power, and air conditioning are functional.”

Montieth confirmed damage to many buildings.

“In an initial assessment of the Cape facilities, about 40 % of buildings we inspected so far have received some damage. So 107 of 216 buildings at the Cape inspected have already been identified with damage.

Launch Complex 39 and surrounding areas are seen during an aerial survey of NASA’s Kennedy Space Center in Florida on Sept. 12, 2017. The survey was performed to identify structures and facilities that may have sustained damage from Hurricane Irma as the storm passed Kennedy on Sept. 10, 2017. KSC reopens on Sept. 10, 2017. Credit: NASA KSC

“Lots of roof and siding damage, Montieth explained on Sept. 13. “We haven’t inspected the beaches yet.

“We have water issues at the Cape. We need water for the chillers to cool the operational buildings.”
Luckily the damage from Irma was less than feared.

“Under Hurricane Matthew there was about $50 million worth of damage between us and our launch partners. We think it will be less this time for Irma but we have a lot more work to do,” noted Montieth.

“The storm wasn’t as bad as expected. You hope for the best and prepare for the worst and that’s what we did. We had a ride-out team on base in a secure facility. Irma traveling over land helped us out. But we still got hit here by over 90 MPH winds gusts and over 58 mph winds – which are hurricane category 1 winds.”

“We also got hit by what we believe are 3 probable small tornadoes that hit the base. That claim is up to the NWS.”

He noted that the X-37B was launched successfully last Friday by SpaceX and that ongoing hurricane preparations and evacuations went to full swing right afterward the morning blastoff.

USAF X-37B military spaceplane blasts off with picturesque water reflections at 10 a.m. EDT (1400 UTC) Sept. 7, 2017 on a SpaceX Falcon 9 rocket from Launch Complex 39A at the Kennedy Space Center. Credit: Ken Kremer/kenkremer.com

Watch for Ken’s continuing onsite X-37B OTV-5 and NASA mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Derelict boat crashed up on shore along the Indian River lagoon in Titusville, FL right after Hurricane Irma pounded the Space Coast on Sept. 10/11, 2017. Credit: Ken Kremer/kenkremer.com
Thrashing waves and winds from Hurricane Irma nearly washed away the roadway past the Max Brewer Bridge, Titusville leading to Playalinda Beach on Sept. 10/11, 2017. Water levels were several feet above normal hours after the storm passed. Credit: Ken Kremer/kenkremer.com
Rotary Rover Front park along the Indian River lagoon in Titusville, FL which offered a magnificent view of the iconic Vehicle Assembly Building and launches from Launch Complex 39A on NASA’s Kennedy Space Center was destroyed by Hurricane Irma on Sept. 10/11, 2017. Credit: Ken Kremer/kenkremer.com
Launch Complex 39A and SpaceX processing hangar at NASA’s Kennedy Space Center survived intact after Hurricane Irma swept by on Sept. 10/11, 2017 in this post storm view taken from Playalinda Beach. Credit: Ken Kremer/kenkremer.com
Launch Complex 39B at NASA’s Kennedy Space Center survived intact after Hurricane Irma swept by on Sept. 10/11, 2017 in this post storm view taken from Playalinda Beach. Credit: Ken Kremer/kenkremer.com
Posted on by Matt Williams

Hubble Spots Pitch Black Hot Jupiter that “Eats Light”

Illustration showing one of the darkest known exoplanets - an alien world as black as fresh asphalt - orbiting a star like our Sun. The day side of the planet, called WASP-12b, eats light rather than reflects it into space. Credit: NASA, ESA, and G. Bacon (STScI)

The study of extra-solar planets has revealed discoveries that have confounded expectations and boggled the mind! Whether it’s Super-Earths that become diamond planets, multiple rocky planets orbiting closely together, or “Hot Jupiters” with traces of gaseous metal in their atmospheres, there’s been no shortage of planets out there for which there is no comparison here in the Solar System.

In this respect, WASP-12b is in good company. This Hot-Jupiter, located in a star system 1400 light years from Earth in the direction of the Auriga constellation, was recently studied by a team of astronomers using the Hubble Space Telescope. Due to the particular nature of its atmosphere, which absorbs the vast majority of light it receives instead of reflecting it, this planet appeared pitch black when observed by the Hubble team.

The study which details their findings, “The Very Low Albedo of WASP-12b from Spectral Eclipse Observations with Hubble“, was recently published in The Astrophysical Journal. Led by Taylor Bell, a researcher at the Institute for Research on Exoplanets (IREx) at McGill University, the team consulted data from the Hubble’s Space Telescope Imaging Spectrograph (STIS) to observe WASP-12b during an optical eclipse.

WASP-12b orbits so close to its star that it is heated to a record-breaking 2500°C. Credit: ESA/C Carreau

Like all Hot Jupiters, WASP-12b is similar in mass to Jupiter (1.35 to 1.43 Jupiter masses) and orbits very close to its star. At a distance of just 3.4 million km (2.115 million mi), or 0.0229 AU, it takes a little over a day to complete a single orbit. Because of its proximity, one side of the planet is constantly facing towards it’s sun – i.e. it is tidally locked with its star.

Because of its orbit, temperatures on the day side of the planet are estimated to reach as high as 2811 K (2538 °C; 4600 °F). It is because of these extreme temperatures that most molecules are unable to survive on the day side of the planet, so clouds cannot form to reflect light back into space. As a result, most incoming light penetrates deep into the planet’s atmosphere, where it is absorbed by hydrogen atoms and converted into heat energy.

This was what Bell and his team noticed as they observed the planet passing behind its star (aka. an optical eclipse). Using the STIS, they monitored the system for any dips in starlight, which would indicate how much reflected light was being given off by the planet. However, their observations did not detect reflected light, which indicated that the sun-facing side was absorbing most of the light it was receiving.

As Bell explained in a NASA press statement, this was quite the unusual find: “We did not expect to find such a dark exoplanet,” he said. “Most hot Jupiters reflect about 40 percent of starlight.” However, observations conducted of the night side of the planet show that things are quite different there. On this side, temperatures are about 1366 K (1093 °C; 2000 °F) cooler, which allows water vapor and clouds to form.

An artist’s impression of WASP 12-b being slowly consumed as a result of its ridiculously tight orbit around its star. Credit: NASA.

Back in 2013, scientists working with the HST detected traces of water vapor in the atmosphere (and possible traces of clouds as well) while studying the day/night boundary. As Bell indicated, this new research just goes to show just how diverse this type of gas giant can be:

“This new Hubble research further demonstrates the vast diversity among the strange population of hot Jupiters. You can have planets like WASP-12b that are 4,600 degrees Fahrenheit and some that are 2,200 degrees Fahrenheit, and they’re both called hot Jupiters. Past observations of hot Jupiters indicate that the temperature difference between the day and night sides of the planet increases with hotter day sides. This previous research suggests that more heat is being pumped into the day side of the planet, but the processes, such as winds, that carry the heat to the night side of the planet don’t keep up the pace.”

Since its discovery in 2008, several telescopes have studied WASP-12b, including Hubble, NASA’s Spitzer Space Telescope, and NASA’s Chandra X-ray Observatory. Previous observations by Hubble’s Cosmic Origins Spectrograph (COS) also revealed that the planet may be losing size and mass due to super-heated material from its atmosphere slowly being accreted onto the star.

This is just the latest find in a slew that has confounded scientists expectations about exoplanets. The more we come to learn about the nature and diversity of these distant worlds, the more tantalizing they seem and the more appealing the prospect of exploring them directly someday becomes!

Further Reading: NASA, IREx, Astrophysical Journal Letters

Posted on by Nancy Atkinson

Loss of Signal: Cassini Spacecraft Plunges Into Saturn

Artist concept of Cassini's last moments at Saturn. Credit: NASA/JPL.

Until the very end, Cassini displayed just how robust and enduring this spacecraft has been throughout its entire 20 years in space and its 13-year mission at Saturn. As Cassini plummeted through the ringed-planet’s atmosphere, its thrusters fought the good fight to keep the antenna pointed at Earth for as long as possible, sending as much of the last drops of science data as it could.

Cassini endured about 40 seconds longer than expected before loss of signal was called at 11:55:46 UTC

“I hope you’re all deeply proud of this accomplishment,” said Cassini Project Manager Earl Maize in JPL’s Mission Control Center after Cassini’s signal was lost. “This has been an incredible mission, and incredible spacecraft and an incredible team. I’m going to call this the end of mission. Project Manager off the net.”

Of course, the actual demise of Cassini took place about an hour and 23 minutes before, as it took that long for the signal to travel the 1.5 billion km distance from Saturn to Earth.

“This is a bittersweet moment for all of us,” said JPL Director Mike Watkins, “but I think it is more sweet than bitter because Cassini has been such an incredible mission. This is a great time to celebrate the hard work and dedication of those who have worked on this mission.”

Watkins added that almost everything we know about Saturn comes from the Cassini mission. “It made discoveries so compelling that we have to back,” he said. “We will go back and fly through the geysers of Encleadus and we’ll go back to explore Titan… These are incredibly compelling targets.”

Cassini program manager at JPL, Earl Maize, left, and spacecraft operations team manager for the Cassini mission at Saturn, Julie Webster, right, embrace after the Cassini spacecraft plunged into Saturn, Friday, Sept. 15, 2017 at NASA’s Jet Propulsion Laboratory in Pasadena, California. Photo Credit: (NASA/Joel Kowsky)

Cassini launched on Oct. 15, 1997, and arrived at Saturn’s in 2004. It studied Saturn’s rings and sent back postcards almost every day of its journeys around the Saturn system, pictures of complex moons, the intriguing rings and the giant gas planet.

It revealed the moon Enceladus as one of the most geothermally active places in our solar system, showing it to be one of the prime targets in the search for life beyond Earth.

Saturn’s active, ocean-bearing moon Enceladus sinks behind the giant planet in a farewell portrait from NASA’s Cassini spacecraft.
Credits: NASA/JPL-Caltech/Space Science Institute

Also, piggybacking along was the Huygens probe to study Saturn’s largest moon, Titan. This landing in 2005 was the first spacecraft to land in the outer solar system.

During its final plunge, Cassini’s instruments captured data on Saturn’s atmosphere, sending a strong signal throughout. As planned, data from eight of Cassini’s science instruments will be providing new insights about Saturn, including hints about the planet’s formation and evolution, and processes occurring in its atmosphere.

This death plunge ensures Saturn’s moons will remain pristine for future exploration.

Over 260 scientists from 17 countries and hundreds of engineers worked with Cassini throughout the entire mission. During Cassini’s final days, mission team members from all around the world gathered at JPL to celebrate the achievements of this historic mission.

Here is the last picture taken by Cassini’s cameras, showing the place where Cassini likely met its demise:

This monochrome view is the last image taken by the imaging cameras on NASA’s Cassini spacecraft. It looks toward the planet’s night side, lit by reflected light from the rings, and shows the location at which the spacecraft would enter the planet’s atmosphere hours later. Credit: NASA/JPL-Caltech/Space Science Institute

If you can’t get enough of Cassini, there will be more information coming about this final data, and of course, you can go look at all the images it has sent back here. Also, NASA has provided an ebook for download that includes information and images from the mission.

Posted on by Matt Williams

Astronomers Spot Hellish World with Titanium in its Atmosphere

Artist's impression showing the exoplanet WASP-19b, in which atmosphere astronomers detected titanium oxide for the first time. Credit: ESO

The hunt for exoplanets has turned up many fascinating case studies. For example, surveys have turned up many “Hot Jupiters”, gas giants that are similar in size to Jupiter but orbit very close to their suns. This particular type of exoplanet has been a source of interest to astronomers, mainly because their existence challenges conventional thinking about where gas giants can exist in a star system.

Hence why an international team led by researchers from the European Southern Observatory (ESO) used the Very Large Telescope (VLT) to get a better look at WASP-19b, a Hot Jupiter located 815 light-years from Earth. In the course of these observations, they noticed that the planet’s atmosphere contained traces of titanium oxide, making this the first time that this compound has been detected in the atmosphere of a gas giant.

The study which describes their findings, titled “Detection of titanium oxide in the atmosphere of a hot Jupiter“, recently appeared in the science journal Nature. Led by Elyar Sedaghati – a recent graduate from the Technical University of Berlin and a fellow at the European Southern Observatory – the team used data collected by the VLT array over the course of a year to study WASP-19b.

Like all Hot Jupiters, WASP-19b has about the same mass as Jupiter and orbits very close to its sun. In fact, its orbital period is so short  – just 19 hours – that temperatures in its atmosphere are estimated to reach as high as 2273 K (2000 °C; 3632 °F). That’s over four times as hot as Venus, where temperatures are hot enough to melt lead! In fact, temperatures on WASP-19b are hot enough to melt silicate minerals and platinum!

The study relied on the FOcal Reducer/low dispersion Spectrograph 2 (FORS2) instrument on the VLT, a multi-mode optical instrument capable of conducting imaging, spectroscopy and the study of polarized light (polarimetry). Using FORS2, the team observing the planet as it passed in front of its star (aka. made a transit), which revealed valuable spectra from its atmosphere.

After carefully analyzing the light that passed through its hazy clouds, the team was surprised to find trace amounts of titanium oxide (as well as sodium and water). As Elyar Sedaghati, who spent 2 years as a student with the ESO to work on this project, said of the discovery in an ES press release:

“Detecting such molecules is, however, no simple feat. Not only do we need data of exceptional quality, but we also need to perform a sophisticated analysis. We used an algorithm that explores many millions of spectra spanning a wide range of chemical compositions, temperatures, and cloud or haze properties in order to draw our conclusions.”

Titanium oxide is a very rare compound which is known to exist in the atmospheres of cool stars. In small quantities, it acts as a heat absorber, and is therefore likely to be partly responsible for WASP-19b experiencing such high temperatures. In large enough quantities, it can prevent heat from entering or escaping an atmosphere, causing what is known as thermal inversion.

This is a phenomena where temperatures are higher in the upper atmosphere and lower further down. On Earth, ozone plays a similar role, causing an inversion of temperatures in the stratosphere. But on gas giants, this is the opposite of what usually happens. Whereas Jupiter, Saturn, Uranus and Neptune experience colder temperatures in their upper atmospheres, temperatures are much hotter closer to the core due to increases in pressure.

The team believes that the presence of this compound could have a substantial effect on the atmosphere’s temperature, structure and circulation. What’s more, the fact that the team was able to detect this compound (a first for exoplanet researchers) is an indication of how exoplanet studies are achieving new levels of detail. All of this is likely to have a profound impact on future studies of exoplanet atmospheres.

The study would also have not been possible were it not for the FORS2 instrument, which was added to the VLT array in recent years. As Henri Boffin, the instrument scientist who led the refurbishment project, commented:

“This important discovery is the outcome of a refurbishment of the FORS2 instrument that was done exactly for this purpose. Since then, FORS2 has become the best instrument to perform this kind of study from the ground.”

Looking ahead, it is clear that the detection of metal oxides and other similar substances in exoplanet atmospheres will also allow for the creation of better atmospheric models. With these in hand, astronomers will be able to conduct far more detailed and accurate studies on exoplanet atmospheres, which will allow them to gauge with greater certainty whether or not any of them are habitable.

So while this latest planet has no chance of supporting life – you’d have better luck finding ice cubes in the Gobi desert! – its discovery could help point the way towards habitable exoplanets in the future. On step closer to finding a world that could support life, or possibly that elusive Earth 2.0!

Further Reading: ESO, Nature

Posted on by Nancy Atkinson

Cassini: The Mission That Will Live Forever

Artist rendition of the Cassini spacecraft over Saturn. Credit: NASA/JPL-Caltech/SSI/Kevin M. Gill.

“With Cassini, we had a rare opportunity and we seized it,” said Linda Spilker, Cassini Mission Scientist.

And on Friday, September 15, we say goodbye to this incredible spacecraft.

Since 2004, Cassini has been orbiting Saturn, exploring the magnificent gas giant planet while weaving through an incredibly diverse assortment of 60-plus icy moons, and skimming along the edges of the complex but iconic icy rings.

Cassini’s findings have revolutionized our understanding of the entire Saturn system, providing intriguing insights on Saturn itself as well as revealing secrets held by moons such as Enceladus, which should be a big iceball but instead is one of the most geothermally active places in our solar system. And thanks to the Huygens lander, we now know Saturn’s largest moon, Titan is eerily Earthlike, but yet totally alien.

“The lasting story of Cassini will likely be its longevity and the monumental amount of scientific discovery,” Cassini Project Manager Earl Maize told me last year. “It was absolutely the right spacecraft in the right place at the right time to capture a huge array of phenomena at Saturn.”

But after 20 years in space, the Cassini spacecraft is running out of fuel, and so Cassini will conduct a sacred act known as ‘planetary protection.’ This self-sacrifice will ensure any potentially habitable moons of Saturn won’t be contaminated sometime in the future if the drifting, unpowered spacecraft were to accidentally crash land there. Microbes from Earth might still be adhering to Cassini, and its RTG power source still generates warmth. It could melt through the icy crust of one of Saturn’s moons, possibly, and reach a subsurface ocean.

Diagram of Cassini’s final week, showing some of the milestones as the spacecraft heads for its plunge into Saturn. Credit: NASA/JPL-Caltech

For a mission this big, this long and this unprecedented, it will end in spectacular fashion. Called the Grand Finale — which actually began last spring — Cassini has made 22 close passes through the small gap between Saturn’s cloud tops and the innermost ring. This series of orbits has sent the spacecraft on an inevitable path towards destruction.

And tomorrow, on its final orbit, Cassini will plunge into Saturn’s atmosphere at tens of thousands of kilometers per hour. Like the science-churning machine it has been throughout its mission, Cassini will continue to conduct science observations until the very end, sending back long-sought after data about Saturn’s atmosphere. But eventually, the spacecraft will be utterly destroyed by the gas planet’s heat and pressure. It will burn up like a meteor, and become part of the planet itself.

There’s no real way to sum up this amazing mission in one article, and so I’ll leave some links and information below for you to peruse.

But I’ll also leave you with this: Instead of feeling like the mission is over, I prefer to think of Cassini as living forever, because of all the data it provided that has yet to be studied. Linda Spilker told me this last year:

“In one way,” Spilker said, “the mission will end. But we have collected this treasure trove of data, so we have decades of additional work ahead of us. With this firehose of data coming back basically every day, we have only been able to skim the cream off the top of the best images and data. But imagine how many new discoveries we haven’t made yet! The search for a more complete understanding of the Saturn system continues, and we leave that legacy to those who come after, as we dream of future missions to continue the exploration we began.”

But if you want to say goodbye to Cassini, scientist Sarah Hörst might have suggested the best way to do it:

You can watch the live video coverage of Cassini’s end of mission on Friday starting at 7 a.m. EDT. on NASA TV

NASA has a great “Grand Finale” feature on its website, which is well worth the visit.

NASA also has all sorts of “Grand Finale” images, graphics and videos available here.

Follow the @CassiniSaturn twitter account for the latest info.

Imaging wizard Kevin Gill has put together a “Visions of Cassini” video with a great compilation of images from the mission. Here’s a shorter two minute version:

Or a longer, two and a half hour version!

These are one of the highest-resolution color images of any part of Saturn’s rings, taken on taken on July 6, 2017, with the Cassini spacecraft narrow-angle camera. This image shows a portion of the inner-central part of the planet’s B Ring. Credit: NASA/JPL-Caltech/Space Science Institute

Posted on by Ken Kremer

Russian-American Trio Blasts Off and Boards International Space Station After Fast Track Trajectory

The Soyuz MS-06 rocket blasts off with the Expedition 53-54 crew towards the International Space Station from the Baikonur Cosmodrome in Kazakhstan, Tuesday, Sept. 12, 2017 (Wednesday, Sept. 13, Kazakh time). Credit: NASA/Bill Ingalls
The Soyuz MS-06 rocket blasts off with the Expedition 53-54 crew towards the International Space Station from the Baikonur Cosmodrome in Kazakhstan, Tuesday, Sept. 12, 2017 (Wednesday, Sept. 13, Kazakh time). Credit: NASA/Bill Ingalls

Barely a week and a half after the thrilling conclusion to the record breaking space endurance mission by NASA astronaut Peggy Whitson, a new Russian-American trio blasted off for the International Space Station (ISS) on a Russian Soyuz capsule and boarded safely early this morning Wednesday, Sept. 13, after arriving as planned on a fast track orbital trajectory.

NASA astronauts Mark Vande Hei, Joe Acaba and Alexander Misurkin of Roscosmos launched aboard the Soyuz MS-06 spacecraft from the Baikonur Cosmodrome in Kazakhstan overnight at 5:17 p.m. Tuesday, Sept. 12, 2017, (2127 GMT), or 3:17 a.m. Baikonur time Wednesday, Sept. 13, on the Expedition 53 mission.

Following the flawless launch and achieving orbit the three man crew executed a perfect four orbit, six hour rendezvous and arrived at the orbiting laboratory complex at 10:55 p.m. EDT Tuesday, Sept. 12, (or Wednesday, Sept. 13, Kazakh time) where they will carry out a jam packed schedule of scientific research in a wide array of fields.

The entire launch sequence aboard the Soyuz rocket performed flawlessly and delivered the Soyuz capsule to its targeted preliminary orbit eight minutes and 45 seconds after liftoff followed by the opening of the vehicles pair of life giving solar arrays and communications antennas.

The whole event from launch to docking was broadcast live on NASA TV.

Soyuz reached the ISS after a rapid series of orbit raising maneuvers over four orbits and six hours to successfully complete all the rendezvous and docking procedures to attach to the station at the Russian Poisk module.

“Contact! We have mechanical contact,” radioed Misurkin.

The Soyuz MS-06 spacecraft carrying NASA astronauts Mark Vande Hei and Joe Acaba and cosmonaut Alexander Misurkin of Roscosmos is seen on the right approaching the International Space Station on Tuesday, Sept. 12, 2017. The spacecraft docked to the station at 10:55 p.m. EDT. Credits: NASA Television

After conducting leak and safety checks the new trio opened the hatches between the Soyuz spacecraft and station at 1:08 a.m. EDT this morning, Sept. 13 and floated into the million pound orbiting outpost.

The arrival of Vande Hei, Acaba and Misurkin restores the station’s multinational habitation to a full complement of six astronaut and cosmonaut crewmembers.

They join Expedition 53 Commander Randy Bresnik of NASA and Flight Engineers Sergey Ryazanskiy of Roscosmos and Paolo Nespoli of ESA (European Space Agency).

The station had been temporarily reduced to a staff of three for 10 days following the departure of the Expedition 52 crew including record setting Whitson, NASA astronaut Jack Fischer and veteran cosmonaut Fyodor Yurchikhin of Roscosmos.

This is the rookie flight for Vande Hei, the second for Misurkin and the third for Acaba. They will remain aboard the station for a planned five month long ISS expedition continuing into early 2018.

Vande Hei was selected as an astronaut in 2009. Misurkin previously flew to the station on the Expedition 35/36 increments in 2013. Acaba was selected as an astronaut in 2004. He flew on space shuttle mission STS 119 and conducted two spacewalks – as well as on the Expedition 31/32 increments in 2012 and has logged a total of 138 days in space.

Originally the Soyuz MS-06 was only to fly with a two person crew – Vande Hei and Misurkin after the Russians decided to reduce their cosmonaut crew from three to two to save money.

Acaba was added to the crew only in March of this year when NASA and Roscosmos brokered an agreement to fill the empty seat with a NASA astronaut, under an arrangement worked out for 5 astronauts seats on Soyuz through a procurement by Boeing, as compensation for an unrelated matter.

The Russian cosmonaut crew cutback enabled Whitson’s mission extension by three months and also proved to be a boon for NASA and science research. It enabled the US/partner USOS crew complement to be enlarged from three to four full time astronauts much earlier than expected.

This allowed NASA to about double the weekly time devoted to research aboard station – a feat not expected to happen until America’s commercial crew vehicles, namely Boeing Starliner and SpaceX Crew Dragon – finally begin inaugural launches next year from the Kennedy Space Center in mid-2018.

With Acaba and Vande Hei now on orbit joining Bresnik and Nespoli, the USOS crew stands at four and will continue.

The six crewmembers will carry out research supporting more than 250 experiments in astrophysics, biology, biotechnology, physical science and Earth science.

“During Expedition 53, researchers will study the cosmic ray particles, demonstrate the benefits of manufacturing fiber optic filaments in microgravity, investigate targeted therapies to improve muscle atrophy and explore the abilities of a new drug to accelerate bone repair,” says NASA.

Among the key investigations involves research on cosmic ray particles reaching Earth using ISS-CREAM, examining effects on the musculoskeletal system and exploring targeted therapies for slowing or reversal of muscle atrophy with Rodent Research 6 (RR-6), demonstrating the benefits of manufacturing fiber optic filaments in a microgravity environment with the Optical Fiber Production in Microgravity (Made in Space Fiber Optics) hardware, and working on drugs and materials for accelerating bone repair with the Synthetic Bone experiment to develop more effective treatments for patients with osteoporosis.

Expedition 53 Flight Engineers Mark Vande Hei and Joe Acaba of NASA and Soyuz Commander Alexander Misurkin of Roscosmos launched from the Baikonur Cosmodrome in Kazakhstan, Tuesday, Sept. 12, 2017 (Wednesday, Sept. 13, Kazakh time), and arrived at the International Space Station at 10:55 p.m. to begin their 5.5-month mission aboard the station. Credits: NASA/Bill Ingalls

Bresnik, Ryazanskiy and Nespoli are scheduled to remain aboard the station until December. Whereas Vande Hei, Acaba and Misurkin are slated to return in February 2018.

Watch this cool Roscosmos video showing rollout of the Soyuz rocket to the Baikonur launch pad and erection in advance of launch. Credit: Roscosmos

Meanwhile one of the first tasks of the new trio will be to assist with the departure of the SpaceX Dragon CRS-12 spacecraft upcoming this Sunday, Sept 17.

Dragon will be detached from the Harmony module using the stations Canadian-built robotic arm on Sunday and released for a splashdown and retrieval in the Pacific Ocean Sunday morning. It is carrying some hardware items as well as scores of science samples.

SpaceX launched its 12th resupply mission to the International Space Station from NASA’s Kennedy Space Center in Florida at 12:31 p.m. EDT on Monday, Aug. 14, 2017. Credit: Ken Kremer/Kenkremer.com

NASA TV will cover the release activities beginning Sunday at 4:30 a.m. EDT.

Visiting vehicle configuration at the International Space Station (ISS) after arrival of the Soyuz MS-06 spacecraft on Sept. 12, 2017. Credit: NASA

Watch for Ken’s onsite space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

The space station’s Expedition 53 crew members are (from left) Joe Acaba, Alexander Misurkin, Mark Vande Hei, Sergey Ryazanskiy, Commander Randy Bresnik and Paolo Nespoli. Credit: NASA
Expedition 53 Crew Insignia
Posted on by Matt Williams

Three Possible Super-Earths Discovered Around Nearby Sun-Like Star

Artist’s impression of a Super-Earth planet orbiting a Sun-like star. Credit: ESO/M. Kornmesser

Since it was launched in 2009, NASA’s Kepler mission has continued to make important exoplanet discoveries. Even after the failure of two reaction wheels, the space observatory has found new life in the form of its K2 mission. All told, this space observatory has detected 5,017 candidates and confirmed the existence of 2,494 exoplanets using the Transit Method during its past eight years in service.

The most recent discovery was made by an international team of astronomers around Gliese 9827 (GJ 9827), a late K-type dwarf star located about 100 light-years from Earth. Using data provided by the K2 mission, they detected the presence of three Super-Earths. This star system is the closest exoplanet-hosting star discovered by K2 to date, which makes these planets well-suited for follow-up studies.

The study which describes their findings, titled “A System of Three Super Earths Transiting the Late K-Dwarf GJ 9827 at Thirty Parsecs“, was recently published online. Led by Dr. Jospeh E. Rodriguez from the Harvard-Smithsonian Center for Astrophysics (CfA), the team includes researchers from the University of Austin, the Massachusetts Institute of Technology (MIT), and the NASA Exoplanet Science Institute (NExSci) at Caltech.

The Transit Method, which remains one of the most trusted means for exoplanet detection, consists of monitoring stars for periodic dips in brightness. These dips correspond to planets passing (aka. transiting) in front of the star causing a measurable drop in the light coming from it. This method also offers unique opportunities to examine light passing through an exoplanet’s atmosphere. As Dr. Rodriguez told Universe Today via email:

“The success of Kepler combined with ground based radial velocity and transit surveys has now led to the discovery of over 4000 planetary system. Since we now know that planets appear to be quite common, the field has shifted its focus to understand architectures, interior structures, and atmospheres. These key properties of planetary systems help us understand some fundamental questions: how do planets form and evolve? What are the terrestrial planets around other stars like, are they similar to Earth in composition and atmosphere?”

These questions were central to the team’s study, which relied on data obtained during Campaign 12 of the K2 mission – from December 2016 to March 2017. After consulting this data, the team noted the presence of three super-Earth sized planets orbiting in a very compact configuration. This system, as they note in their study, was independently and simultaneously discovered by another team from Wesleyan University.

These three planetary objects, designated as GJ 9827 b, c, and d, are located at a distance of about 0.02, 0.04 and 0.06 AU from their host star (respectively). Owing to their sizes and radii, these planets are classified as “Super-Earths”, and have radii of 1.6, 1.2, and 2.1 times the radius of Earth. They are also located very close to their host star, completing orbits within 6.2 days.

The light curve obtained during Campaign 12 of the K2 mission of the GJ 9827 system. Credit: Rodriguez et al., 2017

Specifically, GJ 9827 b measures 1.64 Earth radii, has a mass of up to 4.25 Earth masses, a 1.2 day orbital period, and a temperature of 1,119 K (846 °C; 1555 °F). Meanwhile, GJ 9827 c measures 1.29 Earth radii, has a mass of 2.62 Earth masses, an orbital period of 3.6 days, and a temperature of 774 K (500 °C; 934°F). Lastly, GJ 9827 d measures 2.08 Earth radii, has a mass of 5.3 Earth masses, a 6.2 day period, and a temperature of 648 K (375 °C; 707 °F).

In short, all three planets are very hot, with temperatures that are hot as Venus and Mercury or (in the case of GJ 9827b) is even hotter! Interestingly, these radii and mass estimates place these planets within the transition boundary between terrestrial (i.e. rocky) planets and gas giants. In fact, the team found that GJ 9827 b and c fall in or close to the known gap in radius distribution for planets that are in between these two populations.

In other words, these planets could be rocky or gaseous, and the team won’t know for sure until they can place more accurate constraints on their masses. What’s more, none of these planets are likely to be capable of supporting life, certainly not as we know it! So if you were hoping that this latest find would produce an Earth-analog or potentially habitable planet, you’re sadly mistaken.

Nevertheless, the fact that these planets straddle the radius and mass boundary between terrestrial and gaseous planets – and the fact that this system is the closest planetary system to be identified by the K2 mission – makes the system well-situated for studies designed to probe the interior structure and atmosphere of exoplanets.

Artistic design of the super-Earth orbiting a Sun-like star. Credit: Gabriel Pérez/SMM (IAC)

The reason for this has much to do with the brightness of the host star. In addition to being relatively close to our Sun (~100 light-years), this K-type star is very bright and also relatively small – about 60% the size of our Sun. As a result, any planet passing in front of it would be able to block out more light than if the star were larger. But as noted, there’s also the curious nature of the planets themselves. As Dr. Rodriguez indicated:

“Recently, we have found planets around other stars that have no analogue to a planet in our own system. These are known as “super Earths” and they have radii of 1-3 times the radius of the Earth. To add to the complexity of these planets, their is a clear dichotomy in their composition within this radius range. The larger super Earths (>1.6 x radius of the Earth) appear to be less dense, consistent with a puffy Hydrogen/Helium atmosphere. However, the smaller super Earths are more dense, consistent with an Earth-like composition (rock).

“As mentioned above, the GJ 9827 system hosts three super Earth sized planets. Interestingly, planet c has a radius consistent with it being rocky, planet d is consistent with being puffy, and planet b has a radius that is right on what we believe to be the transition boundary between rock and gas. Therefore, by studying the atmospheres of super-Earths, we may better understand the transition from dense rocky planets to puffier planets with very thick atmospheres (like Neptune).”

Artist’s impression of the super-Earth orbiting closely to its parent star. Credit: ESA/NASA

Looking ahead, the team hopes to conduct further studies to determine the masses of these planets more precisely. From this, they will be able to place better constraints on their compositions and determine if they are Super-Earths, mini gas giants, or some of each. Beyond that, they are to conduct more detailed studies of this system with next-generation instruments like the James Webb Space Telescope (JWST), which is scheduled to launch in 2018.

“I am really interested in studying the atmosphere of GJ 9827 b, whether it is rocky or puffy,” said Dr. Rodriguez. “This planet has a radius at the rock/gas transition but it is very close to its host star. Therefore, by studying the chemical composition of its atmosphere we may better understand the impact of the host star’s proximity has on the evolution of its atmosphere.  To do this we would use JWST to take spectroscopic observations during the transit of GJ 9827b (known as “Transmission Spectroscopy”). From this observations we will gather information on the chemical composition and extent of the planet’s atmosphere.“

Now that we have thousands of extra-solar planet discoveries under our belt, its only natural that research would be shifting towards trying to understand these planets better. In the coming years and decades, we are likely to learn volumes about the respective structures, compositions, atmospheres, and surface features of many distant worlds. One can only imagine what kind of things these studies will turn up!

Further Reading: arXiv

Posted on by David Dickinson

This Weekend: The Moon Photobombs ‘Planet-palooza’ at Dawn

The planetary lineup at dawn from September 12th. Image credit and copyright: Alan Dyer (AmazingSky.com)
September planets
The planetary lineup at dawn (minus the Moon) from September 12th. Image credit and copyright: Alan Dyer (AmazingSky.com).

Following the Moon and wondering where are the fleeting inner solar system planets are this month?

While Jupiter and Saturn sink into the dusk on the far side of the Sun this month, the real action transpires in the dawn sky in mid-September, with a complex set of early morning conjunctions, groupings and occultations.

First, let’s set the stage for the planetary drama. Mercury just passed greatest elongation 18 degrees west of the Sun on September 12th.

The action warms up with a great pre-show on the morning of Saturday, September 16th, when the closest conjunction of two naked eye planets for 2017 occurs, as Mercury passes just 3′ north of Mars. The conjunction occurs at 16:00 UT, favoring the western Pacific region in the dawn hours. The pair is just 17 degrees from the Sun. As mentioned previously, this is the closest conjunction of two naked eye planets in 2017, so close the two will seem to merge to the naked eye and make a nice split with binoculars. This is also one of the first good chances to spy Mars for this apparition, fresh off of its solar conjunction on July 27th, 2017. Mars is now headed towards a favorable opposition next summer on July 27th, 2018, one that’s very nearly as favorable as the historic grand opposition of 2003.

Mars shines at magnitude +1.8 on Saturday morning with a disk 3.6” across, while Mercury shines at magnitude +0.05 with a 64% illuminated disk 6.4” across. Mars is actually 389 million km (2.6 AU) from the Earth this weekend, while Mercury is 158 million km (1.058 AU) distant.

The view looking east on the morning of September 17th. Stellarium

Follow that planet, as Mars also makes a close (12′) pass near Venus on October 5th. At the eyepiece, Venus will look like it has a large moon, just like the Earth!

Think this pass is close? Stick around until August 10th, 2079 and you can actually see Mercury occult (pass in front of) Mars… our cyborg body should be ready to download our consciousness into by then.

Mark your calendars: Mercury occults Mars in 2079. Stellarium

The waning crescent Moon joins the view on Monday, September 18th, making a spectacular series of passes worldwide as it threads its way through the stellar-planetary lineup. Occultations involving the waning Moon are never as spectacular as those involving the waxing Moon, as the bright limb of the Moon leads the way for ingress instead of the dark edge. The best sight to behold will be the sudden reappearance of the planet of star (egress) from behind the waning crescent Moon’s dark limb.

The Moon on Sept 18th
The sky looking east on the morning of September 18th. Stellarium

First up is an occultation of Venus on September 18th centered on 00:55 UT. Unfortunately, this favors the eastern Indian Ocean at dawn, though viewers in Australia and New Zealand can watch the occultation under post dawn daytime skies. The pair is 22 degrees west of the Sun, and the Moon is two days from New during the event. Shining at magnitude -4, it’s actually pretty easy to pick out Venus near the crescent Moon in the daytime. Observers worldwide should give this a try on the 18th as well… folks are always amazed when I show them Venus in the daytime. The last time the Moon occulted Venus was September 3rd, 2016 and the two won’t cross paths again until February 16th, 2018.

The footprint of the occultation of Venus by the Moon. Occult 4.2

Next up, the Moon occults the +1.4 magnitude star Regulus on the 18th at 4:56 UT. Observers across north-central Africa are best placed to observe this event. This is the 11th occultation of Regulus by the Moon in a series of 19, spanning December 2016 to April 2018.

The occultation of Regulus by the Moon. Occult 4.2

The brightest star in the constellation Leo, Regulus is actually 79 light years distant.

Next up, the dwindling waning crescent Moon meets the Red Planet Mars and occults it for the western Pacific at 19:42 UT. Shining at magnitude +1.8 low in the dawn sky, Mars is currently only 3.6” in size, a far cry from its magnificent apparition next summer when it will appear 24.3” in size… very nearly the largest it can appear from the Earth.

The occultation of Mars by the Moon. Occult 4.2

And finally, the slim 2% illuminated Moon will occult the planet Mercury on September 18th centered on 23:21 UT.

The occultation of Mercury by the Moon. Occult 4.2

Mercury occultations are tough, as the planet never strays very far from the Sun. The only known capture I’ve seen was out of Japan back in 2013:

This week’s occultation favors southeast Asia at dawn, and the pair is only 16 degrees west of the Sun. Mercury is gibbous 74% illuminated and 6” in size during the difficult occultation.

We just miss having a simultaneous “multiple occultation” this week. The Moon moves at the span of its half a degree size about once every hour with respect to the starry background, meaning an occultation must occur about 60 minutes apart for the Moon to cover two planets or a planet and a bright star at the same time, a rare once in a lifetime event indeed. The last time this transpired, the Moon covered Venus and Jupiter simultaneously for observers on Ascension Island on the morning of April 23rd 1998.

When is the next time this will occur? We’re crunching the numbers as we speak… watch this space!

Looking into next week, the Moon reaches New phase on Wednesday, September 20th at 5:31 UT/1:31 AM EDT, marking the start of lunation 1172. Can you spy the razor thin Moon Wednesday evening low to the west? Sighting opportunities improve on Thursday night.

Don’t miss this weekend’s dance of the planets in the early dawn sky, a great reason to rise early.

Read about conjunctions, occultations, tales of astronomy and more in our free guide to the Top 101 Astronomical Events for 2017 from Universe Today.

Posted on by Matt Williams

Galaxies Swell due to Explosive Action of New Stars

Artist’s impression of a disk galaxy transforming in to an elliptical galaxy. Stars are actively formed in the massive reservoir of dust and gas at the center of the galaxy. Credit: NAOJ

In 1926, famed astronomer Edwin Hubble developed his morphological classification scheme for galaxies. This method divided galaxies into three basic groups – Elliptical, Spiral and Lenticular – based on their shapes. Since then, astronomers have devoted considerable time and effort in an attempt to determine how galaxies have evolved over the course of billions of years to become these shapes.

One of th most widely-accepted theories is that galaxies changed by merging, where smaller clouds of stars – bound by mutual gravity – came together, altering the size and shape of a galaxy over time. However, a new study by an international team of researchers has revealed that galaxies could actually assumed their modern shapes through the formation of new stars within their centers.

The study, titled “Rotating Starburst Cores in Massive Galaxies at z = 2.5“, was recently published in the Astrophysical Journal Letters. Led by Ken-ichi Tadaki – a postdoctoral researcher with the Max Planck Institute for Extraterrestrial Physics and the National Astronomical Observatory of Japan (NAOJ) – the team conducted observations of distant galaxies in order to get a better understanding of galactic metamorphosis.

Evolution diagram of a galaxy. First the galaxy is dominated by the disk component (left) but active star formation occurs in the huge dust and gas cloud at the center of the galaxy (center). Then the galaxy is dominated by the stellar bulge and becomes an elliptical (or lenticular) galaxy. Credit: NAOJ

This involved using ground-based telescopes to study 25 galaxies that were at a distance of about 11 billion light-years from Earth. At this distance, the team was seeing what these galaxies looked like 11 billion years ago, or roughly 3 billion years after the Big Bang. This early epoch coincides with a period of peak galaxy formation in the Universe, when the foundations of most galaxies were being formed. As Dr. Tadaki indicated in a NAOJ press release:

“Massive elliptical galaxies are believed to be formed from collisions of disk galaxies. But, it is uncertain whether all the elliptical galaxies have experienced galaxy collision. There may be an alternative path.”

Capturing the faint light of these distant galaxies was no easy task and the team needed three ground-based telescopes to resolve them properly. They began by using the NAOJ’s 8.2-m Subaru Telescope in Hawaii to pick out the 25 galaxies in this epoch. Then they targeted them for observations with the NASA/ESA Hubble Space Telescope (HST) and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

Whereas the HST captured light from stars to discern the shape of the galaxies (as they existed 11 billion years ago), the ALMA array observed submillimeter waves  emitted by the cold clouds of dust and gas – where new stars are being formed. By combining the two, they were able to complete a detailed picture of how these galaxies looked 11 billion years ago when their shapes were still evolving.

Observation images of a galaxy 11 billion light-years away. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, Tadaki et al.

What they found was rather telling. The HST images indicated that early galaxies were dominated by a disk component, as opposed to the central bulge feature we’ve come to associate with spiral and lenticular galaxies. Meanwhile, the ALMA images showed that there were massive reservoirs of gas and dust near the centers of these galaxies, which coincided with a very high rate of star formation.

To rule out alternate possibility that this intense star formation was being caused by mergers, the team also used data from the European Southern Observatory’s Very Large Telescope (VLT) – located at the Paranal Observatory in Chile – to confirm that there were no indications of massive galaxy collisions taking place at the time. As Dr. Tadaki explained:

“Here, we obtained firm evidence that dense galactic cores can be formed without galaxy collisions. They can also be formed by intense star formation in the heart of the galaxy.”

These findings could lead astronomers to rethink their current theories about galactic evolution and howthey came to adopt features like a central bulge and spiral arms. It could also lead to a rethink of our models regarding cosmic evolution, not to mention the history of own galaxy. Who knows? It might even cause astronomers to rethink what might happen in a few billion years, when the Milky Way is set to collide with the Andromeda Galaxy.

As always, the further we probe into the Universe, the more it reveals. With every revelation that does not fit our expectations, our hypotheses are forced to undergo revision.

Further Reading: ALMA, Astrophysical Journal Letters

Posted on by Matt Williams

Cassini Conducts a Final Flyby of Titan Before Crashing into Saturn

Illustration of the Cassini probe in orbit of Saturn. The probe will descend into Saturn's atmosphere on Sept. 15th, 2017. Credit: NASA/JPL-Caltech

When the Cassini spacecraft arrived around Saturn on July 1st, 2004, it became the fourth space probe to visit the system. But unlike the Pioneer 11 and Voyager 1 and 2 probes, the Cassini mission was the first to establish orbit around the planet for the sake of conducting long-term research. Since that time, the spacecraft and its accompanying probe – the Huygens lander – have revealed a startling amount about this system.

On Friday, September 15th, the Cassini mission will official end as the spacecraft descends into Saturn’s atmosphere. In part of this final maneuver, Cassini recently conducted one last distant flyby of Titan. This flyby is being referred to informally as “the goodbye kiss” by mission engineers, since it is providing the gravitational push necessary to send the spacecraft into Saturn’s upper atmosphere, where it will burn up.

In the course of this flyby, the spacecraft made its closest approach to Titan on Tuesday, September 12th, at 12:04 p.m. PDT (3:04 p.m. EDT), passing within 119,049 kilometers (73,974 mi) of the moon’s surface. The maneuver was designed to slow the probe down and lower the altitude of its orbit around the planet, which will cause it to descend into Saturn’s atmosphere in a few day’s time.

Artist’s conception of Cassini winging by Saturn’s moon Titan (right) with the planet in the background. Credit: NASA/JPL-Caltech

The flyby also served as an opportunity to collect some final pictures and data on Saturn’s largest moon, which has been a major focal point for much of the Cassini-Huygens mission. These will all be transmitted back to Earth at 18:19 PDT (21:19 EDT) when the spacecraft makes contact, and navigators will use this opportunity to confirm that Cassini is on course for its final dive.

All told, the spacecraft made hundreds of passes over Titan during its 13-year mission. These included a total of 127 precisely targeted encounters at close and far range (like this latest flyby). As Cassini Project Manager Earl Maize, from NASA’s Jet Propulsion Laboratory, said in a NASA press statement:

“Cassini has been in a long-term relationship with Titan, with a new rendezvous nearly every month for more than a decade. This final encounter is something of a bittersweet goodbye, but as it has done throughout the mission, Titan’s gravity is once again sending Cassini where we need it to go.”

In the course of making its many flybys, the Cassini spacecraft revealed a great deal about the composition of Titan’s atmosphere, its methane cycle (similar to Earth’s hydrological cycle) and the kinds of weather it experiences in its polar regions. The probe also provided high-resolution radar images of Titan’s surface, which included topography and images of its northern methane lakes.

Artist depiction of Huygens lander touching down on the surface of Saturn’s largest moon Titan. Credit: ESA

Cassini’s first flyby of Titan took place on July 2nd, 2004 – a day after the spacecraft’s orbital insertion – where it approached to within 339,000 km (211,000 mi) of the moon’s surface. On December 25th, 2004, Cassini released the Huygens lander into the planet’s atmosphere. The probe touched down on January 14th, 2005, taking hundreds of pictures of the moon’s surface in the process.

In November of 2016, the spacecraft began the Grand Finale phase of its mission, where it would make 22 orbits between Saturn and its rings. This phase began with a flyby of Titan that took it to the gateway of Saturn’s’ F-ring, the outermost and perhaps most active ring around Saturn. This was followed by a final close flyby of Titan on April 22nd, 2017, taking it to within 979 km (608 mi) of the moon’s surface.

Throughout its mission, Cassini also revealed some significant things about Saturn’s atmosphere, its hexagonal storms, its ring system, and its extensive system of moons. It even revealed previously-undiscovered moons, such as Methone, Pallene and Polydeuces. Last, but certainly not least, it conducted studies of Saturn’s moon Enceladus that revealed evidence of a interior ocean and plume activity around its southern polar region.

These discoveries are part of the reason why the probe will end its mission by plunging into Saturn’s atmosphere, about two days and 16 hours from now. This will cause the probe to burn up, thus preventing contamination of moons like Titan and Enceladus, where microbial life could possibly exist. Finding evidence of this life will be the main focus of future missions to the Saturn system, which are likely to launch in the next decade.

So long and best wishes, Cassini! You taught so much in the past decade and we hope to follow up on it very soon. We’ll all miss you when you go!

Further Reading: NASA