The first image from the ExoMars craft. Behold the glory of space! Image: ESA/Roscosmos
It doesn’t exactly qualify as eye candy, but the first image from the ESA-Roscosmos ExoMars spacecraft is beautiful to behold in its own way. For most of us, a picture like this would mean something went horribly wrong with our camera. But as the first image from the spacecraft, it tells us that the camera and its pointing system are functioning properly.
ExoMars is a joint project between the European Space Agency and Roscosmos, the Russian Federal Space Agency. It’s an ambitious project, and consists of 2 separate launches. On March 14, 2016, the first launch took place, consisting of the Trace Gas Orbiter (TGO) and the stationary test lander called Schiaparelli, which will be delivered by the Martian surface by the TGO.
TGO will investigate methane sources on Mars, and act as a communications satellite for the lander. The test lander is trying out new landing technologies, which will help with the second launch, in 2020, when a mobile rover will be launched and landed on the Martian surface.
So far, all systems are go on the ExoMars craft during its voyage. “All systems have been activated and checked out, including power, communications, startrackers, guidance and navigation, all payloads and Schiaparelli, while the flight control team have become more comfortable operating this new and sophisticated spacecraft,” says Peter Schmitz, ESA’s Spacecraft Operations Manager.
Three days prior to reaching Mars, the Schiaparelli lander will separate from the TGO and begin its descent to the Martian surface. Though Schiaparelli is mostly designed to gather information about its descent and landing, it still will do some science. It has a small payload of instrument which will function for 2-8 days on the surface, studying the environment and returning the results to Earth.
The TGO will perform its own set of maneuvers, inserting itself into an elliptical orbit around Mars and then spending a year aero-braking in the Martian atmosphere. After that, the TGO will settle into a circular orbit about 400 km above the surface of Mars.
The TGO is hunting for methane, which is a chemical signature for life. It will also be studying the surface features of Mars.
This annotated artist's conception illustrates our current understanding of the structure of the Milky Way galaxy. Image Credit: NASA
Astronomers have found a pair of stellar oddballs out in the edges of our galaxy. The stars in question are a binary pair, and the two companions are moving much faster than anything should be in that part of the galaxy. The discovery was reported in a paper on April 11, 2016, in the Astrophysical Journal Letters.
The binary system is called PB3877, and at 18,000 light years away from us, it’s not exactly in our neighborhood. It’s out past the Scutum-Centaurus Arm, past the Perseus Arm, and even the Outer Arm, in an area called the galactic halo. This binary star also has the high metallicity of younger stars, rather than the low metallicity of the older stars that populate the outer reaches. So PB3877 is a puzzle, that’s for sure.
PB3877 is what’s called a Hyper-Velocity Star (HVS), or rogue star, and though astronomers have found other HVS’s, more than 20 of them in fact, this is the first binary one found. The pair consists of a hot sub-dwarf primary star that’s over five times hotter than the Sun, and a cooler companion star that’s about 1,000 degrees cooler than the Sun.
Hyper-Velocity stars are fast, and can reach speeds of up to 1,198 km. per second, (2.7 million miles per hour,) maybe faster. At that speed, they could cross the distance from the Earth to the Moon in about 5 minutes. But what’s puzzling about this binary star is not just its speed, and its binary nature, but its location.
Hyper-Velocity stars themselves are rare, but PB3877 is even more rare for its location. Typically, hyper velocity stars need to be near enough to the massive black hole at the center of a galaxy to reach their incredible speeds. A star can be drawn toward the black hole, accelerated by the unrelenting pull of the hole, then sling-shotted on its way out of the galaxy. This is the same action that spacecraft can use when they gain a gravity assist by travelling close to a planet.
This video shows how stars can accelerate when their orbit takes them close to the super-massive black holes at the center of the Milky Way.
But the trajectory of PB3877 shows astronomers that it could not have originated near the center of the galaxy. And if it had been ejected by a close encounter with the black hole, how could it have survived with its binary nature intact? Surely the massive pull of the black hole would have destroyed the binary relationship between the two stars in PB3877. Something else has accelerated it to such a high speed, and astronomers want to know what, exactly, did that, and how it kept its binary nature.
Barring a close encounter with the super-massive black hole at the center of the Milky Way, there are a couple other ways that PB3877 could have been accelerated to such a high velocity.
One such way is a stellar interaction or collision. If two stars were travelling at the right vectors, a collision between them could impart energy to one of them and propel it to hyper-velocity. Think of two pool balls on a pool table.
Another possibility is a supernova explosion. It’s possible for one of the stars in a binary pair to go supernova, and eject it’s companion at hyper-velocity speeds. But in these cases, either stellar collision or supernova, things would have to work out just right. And neither possibility explains how a wide-binary system like this could stay intact.
Fraser Cain sheds more light on Hyper-Velocity Stars, or Rogue Stars, in this video.
There is another possibility, and it involves Dark Matter. Dark Matter seems to lurk on the edge of any discussion around something unexplained, and this is a case in point. The researchers think that there could be a massive cocoon or halo of Dark Matter around the binary pair, which is keeping their binary relationship intact.
As for where the binary star PB3788 came from, as they say in the conclusion of their paper, “We conclude that the binary either formed in the halo or was accreted from the tidal debris of a dwarf galaxy by the Milky Way.” And though the source of this star’s formation is an intriguing question, and researchers plan follow up study to verify the supernova ejection possibility, its possible relationship with Dark Matter is also intriguing.
Special Guest: Howard Trottier, a physics professor at Simon Fraser University (SFU) in British Columbia, Canada. Dr. Trottier has recently devoted his time to the development of SFU’s unique Astronomy public outreach program. In the heart of SFU’s main campus is a “”Science Courtyard,”” a high-profile public space devoted to astronomy and anchored by a state-of-the art outreach and teaching observatory. You can learn more about this amazing program here.
We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we’ve started a new system. Instead of adding all of the stories to the spreadsheet each week, we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!
We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.
The Solar and Heliospheric Observatory (SOHO) took these photos of Mercury during its last transit of the Sun on Nov. 8, 2006. Credit: NASA/ESA
Be sure to mark your calendar for May 9. On that day, the Solar System’s most elusive planet will pass directly in front of the Sun. The special event, called a transit, happens infrequently. The last Mercury transit occurred more than 10 years ago, so many of us can’t wait for this next. Remember how cool it was to see Venus transit the Sun in 2008 and again in 2012? The views will be similar with one big difference: Mercury’s a lot smaller and farther away than Venus, so you’ll need a telescope. Not a big scope, but something that magnifies at least 30x. Mercury will span just 10 arc seconds, making it only a sixth as big as Venus.
Two basic types of safe solar filters for telescopes: an aluminized polymer such as Baader film and a dedicated glass solar filter for a particular make and model. Credit: Bob King
Map showing Mercury’s path across the Sun at three key points on May 9: transit start or ingress (left); midpoint and transit end or egress (right). Credit: Tom Ruen with additions by author
If I might make a suggestion, consider buying a sheet of Baader AstroSolar aluminized polyester film and cutting it to size to make your own filter. Although the film’s crinkly texture might make you think it’s flimsy or of poor optical quality, don’t be deceived by appearances.
The material yields both excellent contrast and a pleasing neutral-colored solar image. You can purchase any of several different-sized films to suit your needs either from Astro-Physicsor on Amazon.com. Prices range from $40-90.
Nov. 8, 2006 Transit of Mercury by Dave Kodama
With filter material in hand, just follow these instructions to make your own, snug-fitting telescopic solar filter. Even I can do it, and I kid you not that I’m a total klutz when it comes to building things. If for whatever reason you can’t get a filter, go to Plan B. Put a low power eyepiece in your scope and project an image of the Sun onto a sheet of white paper a foot or two behind the eyepiece.
World map showing where the May 9-10 Mercury transit will be visible. Universal times of the four key contacts (see below for details), mid-transit time and position angle on the Sun’s limb where the planet will first appear and disappear are given at upper left. Credit: Xavier M. Jubier
Since May 9th is a Monday, I’ve a hunch a few of you will be taking the day off. If you can’t, pack a telescope and set it up during lunch hour to share the view with your colleagues. Mercury will spend a leisurely 7 1/2 hours slowly crawling across the Sun’s face, traveling from east to west. The entire transit will be visible across the eastern half of the U.S., most of South America, eastern and central Canada, western Africa and much of western Europe. For the western U.S., Alaska and Hawaii the Sun will rise with the transit already in progress.
Time Zone
Eastern (EDT)
Central (CDT)
Mountain (MDT)
Pacific (PDT)
Transit start
7:12 a.m.
6:12 a.m.
5:12 a.m.
Not visible
Mid-transit
10:57 a.m.
9:57 a.m.
8:57 a.m.
7:57 a.m.
Transit end
2:42 p.m.
1:42 p.m.
12:42 p.m.
11:42 a.m.
Nov. 2006 animation by Hinode. Credit: NASA
At first glance, the planet might look like a small sunspot, but if you look closely, you’ll see it’s a small, perfectly circular black dot compared to the out-of-round sunspots which also possess the classic two-part umbra-penumbra structure. Oh yes, it also moves. Slowly to be sure, but much faster than a typical sunspot which takes nearly two weeks to cross the Sun’s face. With a little luck, a few sunspots will be in view during transit time; compared to midnight Mercury their “black” umbral cores will look deep brown.
I want to alert you to four key times to have your eye glued to the telescope; all occur during the 3 minutes and 12 seconds when Mercury enters and exits the Sun. They’re listed below in Universal Time or UT. To convert UT to EDT, subtract 4 hours; CDT 5 hours; MDT 6 hours, PDT 7 hours, AKDT 8 hours and HST 10 hours.
The black drop effect seen to good advantage during the June 2004 transit of Venus. Credit: Jan Herold
First contact (11:12 UT): Watch for the first hint of Mercury’s globe biting into the Sun just south of the due east point on along the edge of disk’s edge. It’s always a thrill to see an astronomical event forecast years ago happen at precisely the predicted time.
Second contact (11:15 UT): Three minutes and 12 seconds later, the planet’s trailing edge touches the inner limb of the Sun at second contact. Does the planet separate cleanly from the solar limb or briefly remain “connected” by a narrow, black “line”, giving the silhouette a drop-shaped appearance?
This “black drop effect”is caused primarily by diffraction, the bending and interfering of light waves when they pass through the narrow gap between Mercury and the Sun’s edge. You can replicate the effect by bringing your thumb and index finger closer and closer together against a bright backdrop. Immediately before they touch, a black arc will fill the gap between them.
The “black drop effect” can be reproduced by slowly bringing your thumb and index finger together. It’s caused by diffraction combined with blurring from the atmosphere. Credit: Bob King
Third contact (18:39 UT): A minute or less before Mercury’s leading edge touches the opposite limb of the Sun at third contact, watch for the black drop effect to return.
Fourth contact (18:42 UT): The moment the last silhouetted speck of Mercury exits the Sun. Don’t forget to mark your calendar for November 11, 2019, date of the next transit, which also favors observers in the Americas and Europe. After that one, the next won’t happen till 2032.
Other interesting visuals to keep an eye out for is a bright ring or aureole that sometimes appears around the planet caused when our brain exaggerates the contrast of an object against a backdrop of a different brightness. Another spurious optical-brain effect keen-eyed observers can watch for is a central bright spot inside Mercury’s black disk. Use high power to get the best views of these obscure but fascinating phenomena seen by many observers during Mercury transits.
NASA’s Hinode X-ray telescope captured this view of Mercury silhouetted against the Sun’s corona during the Nov. 2006 transit. Similar views are possible in H-alpha light should the planet pass in front of a prominence. Credit: NASA
While I’ve been talking all “white light” observation, the proliferation of relatively inexpensive and portable hydrogen-alpha telescopes in recent years makes them another viewing option with intriguing possibilities. These instruments show solar phenomena beyond the Sun’s limb, including the flaming prominences normally seen only during a total eclipse. That makes it possible to glimpse Mercury minutes in advance of the transit (or minutes after transit end) silhouetted against a prominence or nudging into the rim furry ring of spicules surrounding the outer limb. Wow!
One final note. Be careful never to look directly at the Sun even for a moment during the transit. Keep your eyes safe! When aiming a telescope, the safest and easiest way to center the Sun in the field of view is to shift the scope up and down and back and forth until the shadow the tube casts on the ground is shortest. Try it.
I hope the weather gods smile on you on May 9, but it they don’t or if you live where the transit won’t be visible, Italian astrophysicist Gianluca Masi will stream it live on his Virtual Telescope websitestarting at 11:00 UT (6 a.m CDT).
Here on Earth, we’re always concerned with the weather.
“OK Google, am I going to need an umbrella tomorrow?”
[Google] No, rain is not expected tomorrow in Curtney. The forecast is 20 degrees and partly cloudy.
Uh, it’s pronounced “Courtenay”.
Fine, what if I lived on the Moon? OK Google, am I going to need an umbrella tomorrow on the Moon?
[Google] …
Let’s take Google’s silence for uncertainty.
The names of geological features on the Moon sure evoke mental images of weather. There’s the Ocean of Storms, also known as Oceanus Procellarum, or the Ocean of Clouds – aka Mare Nubium. In fact, most of the regions of the Moon are named after oceans. That’s got to count for something, right?
Many of the features of the moon were thought to be oceans. Credit: NASA
They got these names because the early astronomers thought they were seeing actual oceans on the Moon. They imagined vast seas, where heroic 6-legged creepy bug people plied the icy waves seeking fame, fortune and lunar plunder. I don’t know, like gold cheese or something. Seriously, they were making a lot of this stuff up until telescopes were invented.
But when the NASA astronauts finally set foot on the Moon, they knew they wouldn’t need to pack their snorkeling gear because there weren’t any oceans on the Moon, or really any atmosphere. The Moon is almost as dead and lifeless as space itself.
The storms we see battering the astronauts on every Mars science fiction story just can’t happen on the Moon because there’s no air there.
There’s an ongoing lethal radiation solar wind blowing from the Sun and deep space, but nothing that you’d be able to windsurf too.
So why isn’t there an atmosphere on the Moon? It all comes down to gravity. The Moon has about 1% of the mass of the Earth, which means that it doesn’t have enough gravity to hold onto any gas atmosphere. Anything that it did have would have been blown away by the solar wind billions of years ago.
We did a whole episode on what it would take to terraform the Moon, and it turns out you’d need to constantly replenish the atmosphere.
In fact, this is one of the reasons why the Martian atmosphere is so thin. It was probably thicker in the past, but the solar winds stripped off all the lighter atmosphere long ago. Now it’s just 1% the thickness of the Earth’s atmosphere.
Now, I’ve said that the Moon has almost no atmosphere. But almost no means partly yes. There is in fact an incredibly thin atmosphere surrounding the Moon which measures about a hundred trillionth the thickness of the Earth’s atmosphere.
There are a few sources of this atmosphere. First there’s volcanic outgassing that comes from the Moon. this contributes a little helium and radon. Then there’s the constant micrometeorite bombardment that kicks up pulverized lunar regolith.
Lunar sunrise sketches drawn by Commander E. A. Cernan during the Apollo 17 mission. Credit: NASA
But perhaps the strangest atmospheric feature is a storm that does rage across the surface of the Moon right at the terminator, the exact line between the Moon’s day side and its night side. It turns out the day side of the Moon is positively charged, and the night side is negatively charged.
As the terminator moves, the polarity of the dust flips and it drives it sideways. In fact, the astronauts who walked on the Moon actually reported seeing this. They saw bands or twilight rays in the sky around lunar sunrise/sunset.
Without a thick atmosphere, the surface of the Moon just doesn’t have any appreciable weather and definitely doesn’t have storms like we have on Earth. Mark Watney will need some other reason than weather to be stuck behind on the Moon.
Bigelow Aerospace and United Launch Alliance (ULA) announced they are joining forces to develop and launch the world’s first commercial space habitat to Low Earth Orbit (LEO) by 2020 – potentially as a huge and revolutionary new addition to the International Space Station (ISS).
The expandable habitat will be based on the Bigelow Aerospace B330 module and would be carried to orbit on the most powerful version of ULA’s venerable Atlas V rocket.
Robert Bigelow, founder and president of Bigelow Aerospace, and Tory Bruno, ULA president and CEO announced the partnership on the fully commercial space habitat during a joint media briefing held at the 32nd Space Symposium in Colorado Springs, Colorado on April 11.
“We could not be more pleased than to partner with Bigelow Aerospace and reserve a launch slot on our manifest for this revolutionary mission,” said Tory Bruno, ULA president and CEO.
The B330 boasts an interior volume of 330 cubic meters (12,000 cu ft). It measures 57 feet (17.3 m) in length, weighs 20 tons and offers a design life span of 20 years.
If NASA agrees to attach the B330 to the ISS, the stations habitable volume would grow by a whopping 30% in one giant step.
“The alliance represents the first-ever commercial partnership between a launch provider and a habitat provider,” according to ULA.
The advantage of expandable habitats is that they offer a much better volume to weight ratio compared to standard rigid structures, such as all of the current ISS pressurized modules.
The station based B330 concept is named XBASE or Expandable Bigelow Advanced Station Enhancement.
Schematic of the Bigelow Aerospace B330 expandable module tucked inside the fairing of a ULA Atlas V 552 rocket. Credit: ULA
The additional volume would enable a significant increase in the orbiting outposts ability to support research and development operations and manufacturing processes for NASA and commercial users.
Bigelow further views the B330 and follow on modules as a potential destination for space tourism and a beneficial component for human missions to the Moon and Mars.
“We are exploring options for the location of the initial B330 including discussions with NASA on the possibility of attaching it to the International Space Station (ISS),” said Robert Bigelow, founder and president of Bigelow Aerospace.
“In that configuration, the B330 will enlarge the station’s volume by 30% and function as a multipurpose testbed in support of NASA’s exploration goals as well as provide significant commercial opportunities. The working name for this module is XBASE or Expandable Bigelow Advanced Station Enhancement.”
Bigelow said his firm plans to build two B330 modules by 2020.
The B330 would be tucked inside the cavernous payload fairing of the Atlas V which would launch in the 552 configuration with 5 meter diameter fairing with 5 solid rocket booster attached to the first stage and a dual engine Centaur second stage.
Launch of Bigelow B330 expandable habitat module tucked inside ULA Atlas V payload fairing. Credit: ULA
“When looking for a vehicle to launch our large, unique spacecraft, ULA provides a heritage of solid mission success, schedule certainty and a cost effective solution,” says Bigelow.
The SpaceX falcon 9 fairing is not big enough to house the B330.
“SpaceX, they do not have the capability with the fairing size that is necessary to accommodate the B330. So that is not even a choice,” Bigelow stated.
The B330 partnership announcement follows hot on the heels of last weeks successful launch of Bigelow’s experimental BEAM expandable module on a SpaceX Falcon 9 rocket on a mission to the ISS on April 8.
The Bigelow Expandable Activity Module (BEAM) is an experimental expandable capsule that attaches to the space station. Credits: Bigelow Aerospace, LLC
BEAM is tucked inside the rear truck section of the SpaceX Dragon now berthed at the station. It will soon be attached to a side port on the Harmony module.
“This innovative and game-changing advance will dramatically increase opportunities for space research in fields like materials, medicine and biology,” said Bruno.
“It enables destinations in space for countries, corporations and even individuals far beyond what is available today, effectively democratizing space. We can’t begin to imagine the future potential of affordable real estate in space.”
The B330 could also function as a free flyer but would work best at the station, Bigelow noted at the briefing.
Both of the commercial space taxis being developed under NASA’s commercial crew program (CCP) could dock at the B330; the Boeing Starliner and the SpaceX crew Dragon, Bigelow stated.
Multiple B330 modules could also be joined together in orbit to form a free flying commercial space station.
File photo of Atlas V rocket in with 5 meter diameter payload fairing and 5 solid rocket boosters following rollout to Space Launch Complex 41 at Cape Canaveral Air Force Station, FL. Credit: Ken Kremer – kenkremer.com
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Learn more about SpaceX, ULA, commercial space, NASA Mars rovers, Orion, SLS, ISS, Orbital ATK, Boeing, Space Taxis, NASA missions and more at Ken’s upcoming outreach events:
Apr 17: “NASA and the Road to Mars Human Spaceflight programs”- 1:30 PM at Washington Crossing State Park, Nature Center, Titusville, NJ – http://www.state.nj.us/dep/parksandforests/parks/washcros.html
Artist’s impression of the planet around Alpha Centauri B. Credit: ESO
We know that Earth will die.
Even if we beat global warming, and survive long enough to face and survive the next ice age, Earth will still die. Even if we build a peaceful civilization, protect the planet from asteroids, fight off mutant plagues and whatever else comes our way, life on Earth will die. No matter what we do, the Sun will reach the end of its life, and render Earth uninhabitable.
So reaching for the stars is imperative. What sounds unrealistic to a great many people is a matter of practicality for people knowledgeable about space. To survive, we must have more than Earth.
A project launched by billionaire Yuri Milner, and backed by Mark Zuckerberg, intends to send tiny spacecraft to our nearest stellar neighbour, the Alpha Centauri system. With an expert group assembled to gauge the feasibility, and with the support of eminent cosmologist Stephen Hawking, this idea is gaining traction.
Stephen Hawking thinks reaching out to the stars is more than dreamy space talk: it’s essential to the survival of the human species. He’s smart. We should listen to him.
The distance to the Centauri system is enormous: 4.3 light years, or 1.34 parsecs. The project plans to use lasers to propel the craft, which should mean the travel time would be approximately 30 years, rather than the 30,000 year travel time that current technology restricts us to.
Of course, there are still many technological hurdles to overcome. The laser propulsion system itself is still only a nascent idea. But theoretically it’s pretty sound, and if it can be mastered, should be able to propel space vehicles at close to relativistic speeds.
There are other challenges, of course. The tiny craft will need robust solar sails as part of the propulsion system. And any instruments and cameras would have to be miniaturized, as would any communication equipment to send data back to Earth. But in case you haven’t been paying attention, humans have a pretty good track record of miniaturizing electronics.
Though the craft proposed are tiny, no larger than a microchip, getting them to the Alpha Centauri system is a huge step. Who knows what we’ll learn? But if we’re ever to explore another solar system, it has to start somewhere. And since astronomers think it’s possible that the Centauri system could have potentially habitable planets, it’s a great place to start.
Yuri Gagarin, the first human to break free of Earth's gravity and enter space. Credit: Russian Archives
On April 12th, 1961, the first human being broke free of the gravity bond with Earth, and orbited the planet.
Though most everyone is familiar with the American Apollo astronauts who walked on the Moon, what it took to get there, and the “One small step…” of Neil Armstrong, fewer people are familiar with Yuri Gagarin, the Soviet cosmonaut who was the first human in space. He orbited Earth in his Vostok 1 spacecraft for 108 minutes.
Gagarin became an international celebrity at the time. He received the USSR’s highest honor, the Hero of the Soviet Union. Quite an honor, and quite an achievement for someone who, as a child, survived the Nazi occupation of Russia by living in a tiny mud hut with those members of his family who were not deported for slave labour by the Germans.
The Space Race between the USA and the USSR was in full swing at the time of Gagarin’s flight, and only one month after Gagarin’s historic journey, American astronaut Alan Shepard reached space. But Shepard’s journey was only a 15 minute sub-orbital flight.
Gagarin only has one space flight to his credit, aboard the Vostok 1 in 1961. He did serve as back-up crew for the Soyuz 1 mission though. Gagarin was a test pilot before becoming a cosmonaut, and he died while piloting a Mig-15 fighter jet in 1968.
Space travel in our age is full of ‘firsts.’ It’s the nature of our times. But there can only ever be one first person to leave Earth, and that accomplishment will echo down the ages. Scores of people have been into space now. Their accomplishments are impressive, and they deserve recognition.
A map of the Cosmic Microwave Background (CMB) as captured by the Wilkinson Microwave Anisotropy Probe. Credit: WMAP team
Something’s up in cosmology that may force us to re-write a few textbooks. It’s all centred around the measurement of the expansion of the Universe, which is, obviously, a pretty key part of our understanding of the cosmos.
The expansion of the Universe is regulated by two things: Dark Energy and Dark Matter. They’re like the yin and yang of the cosmos. One drives expansion, while one puts the brakes on expansion. Dark Energy pushes the universe to continually expand, while Dark Matter provides the gravity that retards that expansion. And up until now, Dark Energy has appeared to be a constant force, never wavering.
How is this known? Well, the Cosmic Microwave Background (CMB) is one way the expansion is measured. The CMB is like an echo from the early days of the Universe. It’s the evidence left behind from the moment about 380,000 years after the Big Bang, when the rate of expansion of the Universe stabilized. The CMB is the source for most of what we know of Dark Energy and Dark Matter. (You can hear the CMB for yourself by turning on a household radio, and tuning into static. A small percentage of that static is from the CMB. It’s like listening to the echo of the Big Bang.)
The CMB has been measured and studied pretty thoroughly, most notably by the ESA’s Planck Observatory, and by the Wilkinson Microwave Anisotropy Probe (WMAP). The Planck, in particular, has given us a snapshot of the early Universe that has allowed cosmologists to predict the expansion of the Universe. But our understanding of the expansion of the Universe doesn’t just come from studying the CMB, but also from the Hubble Constant.
The Hubble Constant is named after Edwin Hubble, an American astronomer who observed that the expansion velocity of galaxies can be confirmed by their redshift. Hubble also observed Cepheid variable stars, a type of standard candle that gives us reliable measurements of distances between galaxies. Combining the two observations, the velocity and the distance, yielded a measurement for the expansion of the Universe.
So we’ve had two ways to measure the expansion of the Universe, and they mostly agree with each other. There’ve been discrepancies between the two of a few percentage points, but that has been within the realm of measurement errors.
But now something’s changed.
In a new paper, Dr. Adam Riess of Johns Hopkins University, and his team, have reported a more stringent measurement of the expansion of the Universe. Riess and his team used the Hubble Space Telescope to observe 18 standard candles in their host galaxies, and have reduced some of the uncertainty inherent in past studies of standard candles.
The result of this more accurate measurement is that the Hubble constant has been refined. And that, in turn, has increased the difference between the two ways the expansion of the Universe is measured. The gap between what the Hubble constant tells us is the rate of expansion, and what the CMB, as measured by the Planck spacecraft, tells us is the rate of expansion, is now 8%. And 8% is too large a discrepancy to be explained away as measurement error.
The fallout from this is that we may need to revise our standard model of cosmology to account for this, somehow. And right now, we can only guess what might need to be changed. There are at least a couple candidates, though.
It might be centred around Dark Matter, and how it behaves. It’s possible that Dark Matter is affected by a force in the Universe that doesn’t act on anything else. Since so little is known about Dark Matter, and the name itself is little more than a placeholder for something we are almost completely ignorant about, that could be it.
Or, it could be something to do with Dark Energy. Its name, too, is really just a placeholder for something we know almost nothing about. Maybe Dark Energy is not constant, as we have thought, but changes over time to become stronger now than in the past. That could account for the discrepancy.
A third possibility is that standard candles are not the reliable indicators of distance that we thought they were. We’ve refined our measurements of standard candles before, maybe we will again.
Where this all leads is open to speculation at this point. The rate of expansion of the Universe has changed before; about 7.5 billion years ago it accelerated. Maybe it’s changing again, right now in our time. Since Dark Energy occupies so-called empty space, maybe more of it is being created as expansion continues. Maybe we’re reaching another tipping or balancing point.
The only thing certain is that it is a mystery. One that we are driven to understand.
Recovered SpaceX Falcon 9 rocket arrives back in port overnight at Port Canaveral, Florida on April 12, 2016 following successful launch and landing on April 8 from Cape Canaveral Air Force Station. Credit: Julian Leek
Recovered SpaceX Falcon 9 rocket arrives back in port overnight at Port Canaveral, Florida on April 12, 2016 following successful launch and landing on April 8 from Cape Canaveral Air Force Station. Credit: Julian Leek
The SpaceX Falcon 9 that triumphantly accomplished history’s first upright landing of the spent first stage of a rocket on a barge at sea – after launching a critical cargo payload to orbit for NASA – sailed back into port at Cape Canaveral overnight in the wee hours of this morning, April 12, standing tall.
The recovered 15 story tall Falcon 9 booster arrived back into Port Canaveral, Florida at about 130 a.m. early today, towed atop the ocean going platform that SpaceX dubs an ‘Autonomous Spaceport Drone Ship’ or ASDS.
The ship is named “Of Course I Still Love You” after a starship from a novel written by Iain M. Banks. The landing platform measures only about 170 ft × 300 ft (52 m × 91 m).
A small crowd of excited onlookers and space photographers savored and cheered the incredible moment that is surely changing the face and future of space exploration and travel.
The two stage SpaceX Falcon 9 rocket boasting over 1.5 million pounds of thrust originally launched on Friday, April 8 at 4:43 p.m. EDT from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.
The primary goal of the Falcon 9 launch was carrying the SpaceX Dragon CRS-8 cargo freighter to low Earth orbit on a commercial resupply delivery mission for NASA to the International Space Station (ISS).
Before the launch, SpaceX managers rated the chances of a successful landing recovery rather high.
Three previous attempts by SpaceX to land on a barge at sea were partially successful, as the stage made a pinpoint flyback to the tiny ship but either hit too hard or tipped over in the final moments when a landing leg failed to fully deploy or lock in place.
“We were very optimistic of the chances of a successful landing on this mission,” Hans Koenigsmann told Universe Today in an exclusive post landing interview at the NorthEast Astronomy and Space Forum (NEAF) held in Suffern, NY.
Recovered SpaceX Falcon 9 rocket arrives back in port overnight at Port Canaveral, Florida on April 12, 2016 following successful launch and landing on April 8 from Cape Canaveral Air Force Station. Credit: Julian Leek
Coincidentally, today marks two major anniversaries in the history of space flight; the 55th anniversary of the launch of Russia’s Yuri Gagarin, the first man in space on Vostok-1 on April 12, 1961; and the 35th anniversary of the launch of shuttle Columbia on America’s first space shuttle mission (STS-1) on April 12, 1981 with John Young and Bob Crippen.
The vision of SpaceX’s billionaire founder and CEO Elon Musk is to dramatically slash the cost of access to space by recovering the firms rockets and recycling them for reuse – so that launching rockets will one day be nearly as routine and cost effective as flying on an airplane.
The stage will now be painstakingly inspected, tested and refurbished.
The essential next step after recovery is recycling. Musk said he hopes to re-launch the booster this year.
At liftoff, Dragon was loaded with over 3.5 tons of research experiments and essential supplies for the six man crew living aboard the orbiting science complex.
Watch this launch video from my video camera placed at the pad:
Video Caption: Spectacular blastoff of SpaceX Falcon 9 rocket carrying Dragon CRS-8 cargo freighter bound for the International Space Station (ISS) from Space Launch Complex 40 on Cape Canaveral Air Force Station, FL at 4:43 p.m. EST on April 8, 2016. Up close movie captured by Mobius remote video camera placed at launch pad. Credit: Ken Kremer/kenkremer.com
The Dragon CRS-8 cargo ship successfully arrived at the station on Sunday, April 10 and was joined to the million pound station at the Earth-facing port of the Harmony module.
The secondary objective was to try and land the Falcon 9 first stage on the ASDS done ship located some 200 miles off shore in the Atlantic Ocean.
The action-packed and propulsive landing took place some 10 minutes after liftoff.
In the final moments of the descent to the drone ship, one of the first stage Merlin 1D engines was reignited to slow the boosters descent speed as the quartet of side-mounted landing legs at the boosters base were unfurled, deployed and locked into place.
The entire launch and landing sequence was webcast live on NASA TV and by SpaceX.
The recovered booster atop the “Of Course I Still Love You” barge was towed back to port by the Elsbeth III tug.
“Home sweet home”, said my friend and veteran space photographer Julian Leek, who witnessed the boosters arrival back in port overnight.
“It was really a sight to see. Pilots and tugs did a well coordinated job to bring her in.”
After daylight dawned, a crane lifted the recovered booster into a storage cradle where it will remain upright for a few days. Then it will be lowered and placed horizontally for transport a few miles north to a SpaceX processing hanger back at pad 39A at the Kennedy Space Center.
Recovered SpaceX Falcon 9 rocket moved by crane from drone ship to an upright storage cradle on land at Port Canaveral, Florida on April 12, 2016. Credit: Julian Leek
The booster will be cleaned and defueled, SpaceX spokesman John Taylor told the media.
SpaceX engineers will conduct a series of 12 test firings to ensure all is well operationally and that the booster can be re-launched.
Recovered SpaceX Falcon 9 rocket arrives back in port overnight at Port Canaveral, Florida on April 12, 2016 following successful launch and landing on April 8 from Cape Canaveral Air Force Station. Credit: SpaceX
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Learn more about SpaceX, NASA Mars rovers, Orion, SLS, ISS, Orbital ATK, ULA, Boeing, Space Taxis, NASA missions and more at Ken’s upcoming outreach events:
Apr 12: Hosting Dr. Jim Green, NASA, Director Planetary Science, for a Planetary sciences talk about “Ceres, Pluto and Planet X” at Princeton University; 7:30 PM, Amateur Astronomers Assoc of Princeton, Peyton Hall, Princeton, NJ – http://www.princetonastronomy.org/
Apr 17: “NASA and the Road to Mars Human Spaceflight programs”- 1:30 PM at Washington Crossing State Park, Nature Center, Titusville, NJ – http://www.state.nj.us/dep/parksandforests/parks/washcros.html
