Posted on by Fraser Cain

How Far Back Are We Looking in Time?

How Far Back Are We Looking in Time?

When we look out into space, we’re also looking back into time. Just how far back can we see?

The Universe is a magic time window, allowing us to peer into the past. The further out we look, the further back in time we see. Despite our brains telling us things we see happen at the instant we view them, light moves at a mere 300,000 kilometers per second, which makes for a really weird time delay at great distances.

Let’s say that you’re talking with a friend who’s about a meter away. The light from your friend’s face took about 3.336 nanoseconds to reach you. You’re always seeing your loved ones 3.336 nanoseconds into the past. When you look around you, you’re not seeing the world as it is, you’re seeing the world as it was, a fraction of a second ago. And the further things are, the further back in time you’re looking.

The distance to the Moon is, on average, about 384,000 km. Light takes about 1.28 seconds to get from the Moon to the Earth. If there was a large explosion on the Moon of a secret Nazi base, you wouldn’t see it for just over a second. Even trying to communicate with someone on the Moon would be frustrating as you’d experience a delay each time you talked.

Let’s go with some larger examples. Our Sun is 8 minutes and 20 seconds away at the speed of light. You’re not seeing the Sun as it is, but how it looked more than 8 minutes ago.

On average, Mars is about 14 light minutes away from Earth. When we were watching live coverage of NASA’s Curiosity Rover landing on Mars, it wasn’t live. Curiosity landed minutes earlier, and we had to wait for the radio signals to reach us, since they travel at the speed of light.

When NASA’s New Horizons spacecraft reaches Pluto next year, it’ll be 4.6 light hours away. If we had a telescope strong enough to watch the close encounter, we’d be looking at events that happened 4.6 hours ago.

A Hubble Space Telescope image of Proxima Centauri, the closest star to Earth. Credit: ESA/Hubble & NASA
A Hubble Space Telescope image of Proxima Centauri, the closest star to Earth. Credit: ESA/Hubble & NASA

The closest star, Proxima Centauri, is more than 4.2 light-years away. This means that the Proxima Centurans don’t know who won the last US Election, or that there are going to be new Star Wars movies. They will, however, as of when this video was produced, be watching Toronto make some questionable life choices regarding its mayoral election.

The Eagle Nebula with the famous Pillars of Creation, is 7,000 light-years away. Astronomers believe that a supernova has already gone off in this region, blasting them away. Take a picture with a telescope and you’ll see them, but mostly likely they’ve been gone for thousands of years.

The core of our own Milky Way galaxy is about 25,000 light-years away. When you look at these beautiful pictures of the core of the Milky Way, you’re seeing light that may well have left before humans first settled in North America.

The Andromeda Galaxy will collide with the Milky Way in the future. Credit: Adam Evans
The Andromeda Galaxy. Credit: Adam Evans

And don’t get me started on Andromeda. That galaxy is more than 2.5 million light-years away. That light left Andromeda before we had Homo Erectus on Earth. There are galaxies out there, where aliens with powerful enough telescopes could be watching dinosaurs roaming the Earth, right now.

Here’s where it gets even more interesting. Some of the brightest objects in the sky are quasars, actively feeding supermassive black holes at the cores of galaxies. The closest is 2.5 billion light years away, but there are many much further out. Earth formed only 4.5 billion years ago, so we can see quasars shining where the light had left before the Earth even formed.

The Cosmic Microwave Background Radiation, the very edge of the observable Universe is about 13.8 billion light-years away. This light left the Universe when it was only a few hundred thousand years old, and only now has finally reached us. What’s even stranger, the place that emitted that radiation is now 46 billion light-years away from us.

So crack out your sonic screwdrivers and enjoy your time machine, Whovians. Your ability to look out into space and peer into the past. Without a finite speed of light, we wouldn’t know as much about the Universe we live in and where we came from. What moment in history do you wish you could watch? Express your answer in the form of a distance in light-years.

Posted on by Jason Major

New Horizons Now Close Enough to See Pluto’s Smaller Moons

Animation of images acquired by New Horizons on Jan. 27–Feb. 8, 2015. Hydra is in the yellow square, Nix is in the orange. (Credit: NASA/Johns Hopkins APL/Southwest Research Institute.)

Now on the final leg of its journey to distant Pluto the New Horizons spacecraft has been able to spot not only the dwarf planet and its largest moon Charon, but also two of its much smaller moons, Hydra and Nix – the latter for the very first time!

The animation above comprises seven frames made of images acquired by New Horizons from Jan. 27 to Feb. 8, 2015 while the spacecraft was closing in on 115 million miles (186 million km) from Pluto. Hydra is noted by a yellow box and Nix is in the orange. (See a version of the animation with some of the background stars and noise cleared out here.)

What’s more, these images have been released on the 85th anniversary of the first spotting of Pluto by Clyde Tombaugh at the Lowell Observatory in Flagstaff, AZ.

“Professor Tombaugh’s discovery of Pluto was far ahead its time, heralding the discovery of the Kuiper Belt and a new class of planet. The New Horizons team salutes his historic accomplishment.”
– Alan Stern, New Horizons PI, Southwest Research Institute

Launched Jan. 19, 2006, New Horizons will make its closest pass of Pluto and Charon on July 14 of this year. It is currently 32.39 AU from Earth – over 4.84 billion kilometers away.

“It’s thrilling to watch the details of the Pluto system emerge as we close the distance to the spacecraft’s July 14 encounter,” said New Horizons science team member John Spencer from the Southwest Research Institute (SwRI). “This first good view of Nix and Hydra marks another major milestone, and a perfect way to celebrate the anniversary of Pluto’s discovery.”

Along with the distance between Earth and Pluto, New Horizons is also bridging the gap of history: a portion of Mr. Tombaugh’s ashes are being carried aboard the spacecraft, as well as several historic mementos.

Annotated and unannotated versions of the LORRI images (top and bottom); the right side has had Pluto's glare and additional background stars removed. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)
Annotated and unannotated versions of the LORRI images from Feb. 8 (top and bottom); the right side has had Pluto’s glare and additional background stars removed. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Each frame in the animation is a combination of five 10-second images taken with New Horizons’ Long-Range Reconnaissance Imager (LORRI) using a special mode that increases sensitivity at the expense of resolution. Celestial north is inclined 28 degrees clockwise from the “up” direction in these images.

The dark streaks are a result of overexposure on the digital camera’s sensitive detector.

Pluto and its moons, most of which were discovered while New Horizons was in development and en route. Charon was found in 1978, Nix and Hydra in 2005, Kerberos in 2011 and Styz in 2012. The New Horizons mission launched in 2007. Picture taken by the Hubble Space Telescope. Credit: NASA
Pluto and its moons, most of which were discovered while New Horizons was in development and en route. Charon was found in 1978, Nix and Hydra in 2005, Kerberos in 2011, and Styz in 2012.  Credit: NASA/HST

Pluto has a total of five known moons: Charon, Hydra, Nix, Styx, and Kerberos. Pluto and Charon are within the glare of the image exposures and can’t be resolved separately, and Styx and Kerberos are too dim to be detected yet. But Hydra and Nix, each around 25–95 miles (40–150 km) in diameter, could be captured on camera.

More precise measurements of these moons’ sizes – and whether or not there may be even more satellites in the Pluto system – will be determined as New Horizons approaches its July flyby date.

Learn more about the New Horizons mission here.

Source: NASA

Posted on by Nancy Atkinson

The Moment We’ve been Waiting For: First New Images of Pluto from New Horizons

Pluto and Charon, the largest of Pluto's five known moons, seen Jan. 25 and 27, 2015, through the telescopic Long-Range Reconnaissance Imager (LORRI) on NASA's New Horizons spacecraft. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Here we go! New Horizons is now on approach and today – on the anniversary of Pluto discoverer Clyde Tombaugh’s birth – the spacecraft has sent back its first new images of the Pluto system. The images aren’t Earth-shattering (Pluto-shattering?) but they do represent the mission is closing in on its target, and will allow the New Horizons engineers to precisely aim the spacecraft as it continues its approach.

The photos were taken with the telescopic Long-Range Reconnaissance Imager (LORRI) on January 25 and 27, 2015.

“Pluto is finally becoming more than just a pinpoint of light,” said Hal Weaver, New Horizons project scientist. “LORRI has now resolved Pluto, and the dwarf planet will continue to grow larger and larger in the images as New Horizons spacecraft hurtles toward its targets. The new LORRI images also demonstrate that the camera’s performance is unchanged since it was launched more than nine years ago.”

A comparison of images of Pluto and its large moon Charon, taken in July 2014 and January 2015. Between takes, New Horizons had more than halved its distance to Pluto, from about 264 million miles (425 million kilometers) to 126 million miles (203 million kilometers). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
A comparison of images of Pluto and its large moon Charon, taken in July 2014 and January 2015. Between takes, New Horizons had more than halved its distance to Pluto, from about 264 million miles (425 million kilometers) to 126 million miles (203 million kilometers). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

New Horizons was about 203 million kilometers (126 million miles) away from Pluto when it began taking images. Pluto appears as a pixelated smudge, and New Horizons is only close enough so that just Pluto and its largest moon, Charon are visible. In this current view from LORRI, Pluto is about 2 pixels and Charon is 1, compared to 1 pixel and 0.5 pixels last July. The images were magnified four times to make Pluto and Charon more visible.

NASA says that over the next few months, LORRI will take hundreds of pictures of Pluto, against a starry backdrop, to refine the team’s estimates of New Horizons’ distance to Pluto. As in these first images, the Pluto system will resemble little more than bright dots in the camera’s view until late spring. However, mission navigators can still use such images to design course-correcting engine maneuvers to direct the spacecraft for a more precise approach. The first such maneuver based on these optical navigation images, or OpNavs, is scheduled for March 10.

The image of Pluto and its moon Charon, taken by NASA’s New Horizons spacecraft, was magnified four times to make the objects more visible. Over the next several months, the apparent sizes of Pluto and Charon, as well as the separation between them, will continue to expand in the images. Image Credit: NASA/JHU APL/SwRI
The image of Pluto and its moon Charon, taken by NASA’s New Horizons spacecraft, was magnified four times to make the objects more visible. Over the next several months, the apparent sizes of Pluto and Charon, as well as the separation between them, will continue to expand in the images.
Image Credit:
NASA/JHU APL/SwRI

Closest approach for the spacecraft will be on July 14.

These first images represent a milestone.

“These images of Pluto, clearly brighter and closer than those New Horizons took last July from twice as far away, represent our first steps at turning the pinpoint of light Clyde saw in the telescopes at Lowell Observatory 85 years ago, into a planet before the eyes of the world this summer,” said Alan Stern, New Horizons principal investigator. “This is our birthday tribute to Professor Tombaugh and the Tombaugh family, in honor of his discovery and life achievements — which truly became a harbinger of 21st century planetary astronomy.”

During its flyby, New Horizons will be characterizing the global geology and topography of Pluto and Charon, mapping their surface compositions and temperatures, examining Pluto’s atmospheric composition and structure, studying Pluto’s smaller moons, and searching for new moons and rings.

Sources: NASA, JHUAPL

Posted on by Ken Kremer

Most Powerful Atlas V Delivers a Most Spectacular Nighttime Sky Show Launch for US Navy

Blastoff of ULA Atlas V rocket lofting MUOS-3 to orbit for the US Navy from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: Alan Walters/AmericaSpace

Blastoff of ULA Atlas V rocket lofting MUOS-3 to orbit for the US Navy from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: Alan Walters/AmericaSpace
See launch gallery below![/caption]

Launching on its milestone 200th mission, the most powerful version of the venerable Atlas-Centaur rocket put on a most spectacular nighttime sky show on Tuesday evening, (Jan. 20) that mesmerized spectators along the Florida Space Coast on a mission to deliver a powerful new next-generation communications satellite to orbit for the US Navy.

The United Launch Alliance (ULA) Atlas V rocket carrying the third Mobile User Objective System satellite (MUOS-3) for the United States Navy successfully launched to geostationary orbit from Space Launch Complex-41 at 8:04 p.m. EST from Cape Canaveral Air Force Station, Florida on Jan. 20, 2015.

The MUOS-3 launch opened ULA’s planned 13 mission manifest for 2015 with a boisterous bang as the Atlas V booster thundered off the seaside space coast pad.

Streak shot of United Launch Alliance (ULA) Atlas V rocket carrying the third Mobile User Objective System satellite to orbit for the United States Navy as it launched from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: John Studwell/AmericaSpace
Streak shot of United Launch Alliance (ULA) Atlas V rocket carrying the third Mobile User Objective System satellite to orbit for the United States Navy as it launched from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: John Studwell/AmericaSpace

The MUOS constellation is a next-generation narrowband US Navy tactical satellite communications system designed to significantly improve ground communications to US forces on the move and around the globe.

“The ULA team is honored to deliver this critical mission into orbit for the U.S. Navy and U.S. Air Force with the support of our many mission partners,” said Jim Sponnick, ULA vice president, Atlas and Delta Programs.

This is the third satellite in the MUOS series and will provide military users 10 times more communications capability over existing systems, including simultaneous voice, video and data, leveraging 3G mobile communications technology. It was built by Lockheed Martin.

Launch of ULA Atlas V rocket sending MUOS-3 satcom to orbit for the US Navy from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: Julian Leek
Launch of ULA Atlas V rocket sending MUOS-3 satcom to orbit for the US Navy from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: Julian Leek

The unmanned Atlas V expendable rocket launched in its mightiest configuration known as the Atlas V 551.

The 206 foot-tall rocket features a 5-meter diameter payload fairing, five Aerojet Rocketdyne first stage strap on solid rocket motors and a single engine Centaur upper stage powered by the Aerojet Rocketdyne RL10C-1 engine.

The first stage is powered by the Russian-built dual nozzle RD AMROSS RD-180 engine. Combined with the five solid rocket motors, the Atlas V first stage generates over 2.5 million pounds of liftoff thrust.

The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen and delivers 860,200 lb of thrust at sea level.

And the rocket needed all that thrust because the huge MUOS-3 was the heftiest payload lofted by an Atlas V booster, weighing in at some 15,000 pounds.

“The MUOS-3 spacecraft is the heaviest payload to launch atop an Atlas V launch vehicle. The Atlas V generated more than two and half million pounds of thrust at liftoff to meet the demands of lifting this nearly 7.5-ton satellite,” noted Sponnick.

The Atlas V 551 rockets into the darkened Florida sky at 8:04 p.m. EST Tuesday, 20 January, to deliver MUOS-3 into orbit. Photo Credit: Mike Killian / AmericaSpace
The Atlas V 551 rockets into the darkened Florida sky at 8:04 p.m. EST Tuesday, 20 January, to deliver MUOS-3 into orbit. Photo Credit: Mike Killian / AmericaSpace

The first Atlas rocket was first launched some 52 years ago.

“Today’s launch was the 200th Atlas-Centaur launch – a very sincere congratulations to the many women and men responsible for the incredible success of the Centaur upper stage over the last 5 decades!”

Overall this was the 52nd Atlas V mission and the fifth in the Atlas V 551 configuration.

The Atlas V 551 version has previously launched two prominent NASA planetary science missions including the New Horizons mission in 2006 that is about to reach Pluto and the Juno orbiter in 2011 that will arrive at Jupiter in July 2016. It was also used to launch MUOS-1 and MUOS-2.

United Launch Alliance successful MUOS-3 mission tonight! 20 Jan 2015. Photo Credit: Matthew Travis / Zero-G News
United Launch Alliance successful MUOS-3 mission tonight! 20 Jan 2015. Photo Credit: Matthew Travis / Zero-G News

ULA’s second launch in 2015 thunders aloft from the US West Coast with NASA’s Soil Moisture Active Passive mission (SMAP) next week.

SMAP is the first US Earth-observing satellite designed to collect global observations of surface soil moisture.

SMAP will blastoff from Space Launch Complex 2 at Vandenberg AFB at 9:20 a.m. EST (6:20 a.m. PST) on ULA’s Delta II rocket.

A United Launch Alliance (ULA) Atlas V rocket carrying the third Mobile User Objective System satellite for the United States Navy launched from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: United Launch Alliance
A United Launch Alliance (ULA) Atlas V rocket carrying the third Mobile User Objective System satellite for the United States Navy launched from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: United Launch Alliance

In another major milestone coming soon, the Atlas V is right now being man rated since it was chosen to launch the Boeing CST-100 space taxi, which NASA selected as one of two new commercial crew vehicles to launch US astronauts to the ISS as soon as 2017.

A United Launch Alliance (ULA) Atlas V rocket carrying the third Mobile User Objective System satellite for the United States Navy launched from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: United Launch Alliance
A United Launch Alliance (ULA) Atlas V rocket carrying the third Mobile User Objective System satellite for the United States Navy launched from Space Launch Complex-41 at 8:04 p.m. EST on Jan. 20, 2015. Credit: United Launch Alliance

The next Atlas launch involves NASA’s Magnetospheric Multiscale Mission (MMS) to study Earth’s magnetic reconnection. It is scheduled for launch on an Atlas V 421 booster on March 12 from Cape Canaveral. See my up close visit with MMS and NASA Administrator Charles Bolden at NASA Goddard Space Flight Center detailed in my story – here.

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

Ken Kremer

Posted on by Tim Reyes

It Looks Like These Are All the Bright Kuiper Belt Objects We’ll Ever Find

The presently known largest trans-Neptunian objects (TNO) - are likely to be surpassed by future discoveries. Which of these trans-Neptunian objects (TNO) would you call planets and which "dwarf planets"? (Illustration Credit: Larry McNish, Data: M.Brown)

The self-professed “Pluto Killer” is at it again. Dr. Michael Brown is now reminiscing about the good old days when one could scour through sky survey data and discover big bright objects in the Kuiper Belt. In his latest research paper, Brown and his team have concluded that those days are over.

Ten years ago, Brown discovered what is now known as the biggest Kuiper Belt object – Eris. Brown’s team found others that rivaled Pluto in size and altogether, these discoveries led to the demotion of Pluto to dwarf planet. Now, using yet another sky survey data set but with new computer software, Brown says that its time to move on.

Instigators of the big heist - David Rabinowitz, Brown and Chad Trujillo, left to right. The researchers discovered dozens of Kuiper Belt objects (KBO) including six of the eight largest KBOs including the largest, Eris.
Instigators of the big heist – Rabinowitz, Brown and Trujillo, left to right. The researchers co-discovered dozens of Kuiper Belt objects (KBO) including nine of the ten largest KBOs including the largest, Eris.

Like the famous Bugs Bunny cartoon, its no longer Rabbit Season or Duck Season and as Bugs exclaims to Elmer Fudd, there is no more bullets. Analyzing seven years worth of data, Brown and his team has concluded we are fresh out of Pluto or Charon-sized objects to be discovered in the Kuiper Belt. But for Dr. Brown, perhaps it now might be Oort Cloud season.

His latest paper, A Serendipitous All Sky Survey For Bright Objects In The Outer Solar System, in pre-print, describes the completion of analysis of two past sky surveys covering the northern and southern hemisphere down to 20 degrees in Galactic latitude. Using revised computer software, his team scoured through the data sets from the Catalina Sky Survey (CSS) and the Siding Spring Survey (SSS). The surveys are called “fast cadence surveys” and they primarily search for asteroids near Earth and out to the asteroid belt. Instead Brown’s team used the data to look at image frames spaced days and months apart.

Update: In a Twitter communique, Dr. Brown stated, “I would say we’re out of BRIGHT ones, not big ones. Could be big ones lurking far away!” His latest work involved a southern sky survey (SSS) to about magnitude 19 and the northern survey (CSS) to 21. Low albedo (dark) and more distant KBOs might be lurking beyond the detectability of these surveys that are in the range of Charon to Pluto in size.

Animation showing the movement of Eris on the images used to discover it. Eris is indicated by the arrow. The three frames were taken over a period of three hours. (Credit: Brown, et al.)
Animation showing the movement of Eris on the images used to discover it. Eris is indicated by the arrow. The three frames were taken over a period of three hours. More images over several weeks were necessary to determine its orbit.(Credit: Brown, et al.)

Objects at Kuiper Belt distances move very slowly. For example, Pluto orbits the Sun at about 17,000 km/hr (11,000 mph), taking 250 years to complete one orbit. These are speeds that are insufficient to maintain ven a low-Earth orbit. Comparing two image frames spaced just hours apart will find nearby asteroids moving relative to the star fields but not Kuiper belt objects. So using image frames spaced days, weeks or even months apart, they searched again. Their conclusion is that all the big Kuiper belt objects have been found.

The only possibility of finding another large KBO lies in a search of the galactic plane which is difficult due to the density of Milky Way’s stars in the field of view. The vast number of small bodies in the Kuiper belt and Oort Cloud lends itself readily to statistical analysis. Brown states that there is a 32% chance of finding another Pluto-sized object hiding among the stars of the Milky Way.

Artists concept of the view from Eris with Dysnomia in the background, looking back towards the distant sun. Credit: Robert Hurt (IPAC)
Artists concept of the view from Eris with Dysnomia in the background, looking back towards the distant sun. Credit: Robert Hurt (IPAC)

Dr. Brown also released a blog story in celebration of the discovery of the largest of the Kuiper Belt objects, Eris, ten years ago last week. Ten years of Eris, reminisces about the great slew of small body discoveries by Dr. Brown, Dr. Chad Trujillo of Gemini Observatory and Dr. David Rabinowitz of Yale Observatory.

Brown encourages others to take up this final search right in the galactic plane but apparently his own intentions are to move on. What remains to be seen — that is, to be discovered — are hundreds of large “small” bodies residing in the much larger region of the Oort Cloud. These objects are distributed more uniformly throughout the whole spherical region that the Cloud defines around the Sun.

Furthermore, Dr. Brown maintains that there is a good likelihood that a Mars or Earth-sized object exists in the Oort Cloud.

Small bodies within our Solar System along with exo-planets are perhaps the hottest topics and focuses of study in Planetary Science at the moment. Many graduate students and seasoned researchers alike are gravitating to their study. There are certainly many smaller Kuiper belt objects remaining to be found but more importantly, a better understanding of their makeup and origin are yet to be revealed.

Artist's concept of the Dawn spacecraft at the protoplanet Ceres Illustration of Dawn's approach phase and RC3 orbit This artist’s concept of NASA’s Dawn spacecraft shows the craft orbiting high above Ceres, where the craft will arrive in early 2015 to begin science investigations. (Image credit: NASA/JPL-Caltech)
Artist’s concept of the Dawn spacecraft at the protoplanet Ceres Illustration of Dawn’s approach phase and RC3 orbit This artist’s concept of NASA’s Dawn spacecraft shows the craft orbiting high above Ceres, where the craft will arrive in early 2015 to begin science investigations. (Image credit: NASA/JPL-Caltech)

Presently, the Dawn spacecraft is making final approach to the dwarf planet Ceres in the Asteroid belt. The first close up images of Ceres are only a few days away as Dawn is now just a couple of 100 thousand miles away approaching at a modest speed. And much farther from our home planet, scientists led by Dr. Alan Stern of SWRI are on final approach to the dwarf planet Pluto with their space probe, New Horizons. The Pluto system is now touted as a binary dwarf planet. Pluto and its moon Charon orbit a common point (barycenter) in space that lies between Pluto and Charon.

So Dr. Brown and team exits stage left. No more dwarf planets – at least not soon and not in the Kuiper belt. Will that upstage what is being called the year of the Dwarf Planet?

But next up for close inspection for the first time are Ceres, Pluto and Charon. It should be a great year.

The relative sizes of the inner Solar System, Kuiper Belt and the Oort Cloud. (Credit: NASA, William Crochot)
The relative sizes of the inner Solar System, Kuiper Belt and the Oort Cloud. (Credit: NASA, William Crochot)

References:

A Serendipitous All Sky Survey For Bright Objects In The Outer Solar System

Ten Years of Eris

2015, NASA’s Year of the Dwarf Planet, Universe Today

What is the Kuiper Belt?, Universe Today

Posted on by Nancy Atkinson

Did You Know There are 9 Secret Items Hidden on Pluto’s New Horizons Mission?

This object is a stowaway on board New Horizons. Credit: JHU/APL

The New Horizons spacecraft is now just a few months away from its encounter with Pluto and the Kuiper Belt, arriving in July, 2015. Back in 2008, the New Horizons team revealed the secret stowaways they had hidden on board the spacecraft. Nine objects (can you guess why there are nine?!) were attached and sent along on the ten-year journey to the outer reaches of our Solar System. Believe it or not, included in the items are one actual person, and parts of several thousands of other people…

Here’s the complete list:

1. One actual person. Well, part of an actual person. A portion of Pluto discoverer Clyde Tombaugh’s ashes were put in a container and attached to the underside of the spacecraft – see image above. Here’s the inscription on the container: “Interned herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system’s ‘third zone’ Adelle and Muron’s boy, Patricia’s husband, Annette and Alden’s father, astronomer, teacher, punster, and friend: Clyde W. Tombaugh (1906-1997).”

2. Me and about 434,000 other people, too! The “Send Your Name to Pluto” CD-ROM with more than over four hundred thousand names of people who wanted to participate in this great journey of exploration. I’m pumped about being along for the ride, and I hope you are on board, too!

3. A CD-ROM with pictures of New Horizons project personnel.

4. A Florida state quarter, from the state where New Horizons was launched.

5. A Maryland state quarter, from the state where New Horizons was built.

6. A small piece cut from SpaceShip One is installed on New Horizons’ lower inside deck, with a two-sided inscription. Front: “To commemorate its historic role in the advancement of spaceflight, this piece of SpaceShip One is being flown on another historic spacecraft: New Horizons. New Horizons is Earth’s first mission to Pluto, the farthest known planet in our solar system.” Back: “SpaceShip One was Earth’s first privately funded manned spacecraft. SpaceShip One flew from the United States of America in 2004.”

Piece from SpaceShip One. Credit: JHU/APL
Piece from SpaceShip One. Credit: JHU/APL

7. A U.S. Flag.

8. Another version of a U.S. Flag.

9. The 1991 U.S. stamp proclaiming, “Pluto: Not Yet Explored”

Pluto US postal stamp from 1991. Credit: JHU/APL
Pluto US postal stamp from 1991. Credit: JHU/APL

New Horizons’ principal investigator Dr. Alan Stern disclosed the list of items at a ceremony at Smithsonian National Air and Space Museum’s Udvar-Hazy Center, where a model of the New Horizons spacecraft was added to the museum. Back in 2008, Stern petitioned the U.S. Postal Service to issue a new stamp for Pluto after the spacecraft arrived at Pluto, maybe something like this:

Proposed new stamp for New Horizons. Credit: JHU/APL
Proposed new stamp for New Horizons. Credit: JHU/APL

Source: New Horizons website

We originally wrote this in 2008, but we thought you’d get a kick out of it since New Horizons is so close. We made a couple of updates to the text.

Posted on by Tim Reyes

The Dark Energy Survey Begins to Reveal Previously Unknown Trans-Neptunian Objects

An artist's concept of a trans-Neptunian object(TNOs). The distant sun is reduced to a bright star at a distance of over 3 billion miles. The Dark Energy Survey (DES) has now released discovery of more TNOs. (Illustration Credit: NASA)

Sometimes when you stare at something long enough, you begin to see things. This is not the case with optical sensors and telescopes. Sure, there is noise from electronics, but it’s random and traceable. Stargazing with a telescope and camera is ideal for staring at the same patches of real estate for very long and repeated periods. This is the method used by the Dark Energy Survey (DES), and with less than one percent of the target area surveyed, astronomers are already discovering previously unknown objects in the outer Solar System.

The Dark Energy Survey is a five year collaborative effort that is observing Supernovae to better understand the structures and expansion of the universe. But in the meantime, transient objects much nearer to home are passing through the fields of view. Trans-Neptunian Objects (TNOs), small icy worlds beyond the planet Neptune, are being discovered. A new scientific paper, released as part of this year’s American Astronomical Society gathering in Seattle, Washington, discusses these newly discovered TNOs. The lead authors are two undergraduate students from Carleton College of Northfield, Minnesota, participating in a University of Michigan program.

The Palomar Sky Survey (POSS-1, POSS-2), the Sloan Digital Sky Survey, and every other sky survey have mapped not just the static, nearly unchanging night sky, but also transient events such as passing asteroids, comets, or novae events. The Dark Energy Survey is looking at the night sky for structures and expansion of the Universe. As part of the five year survey, DES is observing ten select 3 square degree fields for Type 1a supernovae on a weekly basis. As the survey proceeds, they are getting more than anticipated. The survey is revealing more trans-Neptunian objects. Once again, deep sky surveys are revealing more about our local environment – objects in the farther reaches of our Solar System.

DES is an optical imaging survey in search of Supernovae that can be used as weather vanes to measure the expansion of the universe. This expansion is dependent on the interaction of matter and the more elusive exotic materials of our Universe – Dark Energy and Dark Matter. The five year survey is necessary to achieve a level of temporal detail and a sufficient number of supernovae events from which to draw conclusions.

In the mean time, the young researchers of Carleton College – Ross Jennings and Zhilu Zhang – are discovering the transients inside our Solar System. Led by Professor David Gerdes of the University of Michigan, the researchers started with a list of nearly 100,000 observations of individual transients. Differencing software and trajectory analysis helped identify those objects that were trans-Neptunian rather than asteroids of the inner Solar System.

While asteroids residing in the inner solar system will pass quickly through such small fields, trans-Neptunian objects (TNOs) orbit the Sun much more slowly. For example, Pluto, at an approximate distance of 40 A.U. from the Sun, along with the object Eris, presently the largest of the TNOs, has an apparent motion of about 27 arc seconds per day – although for a half year, the Earth’s orbital motion slows and retrogrades Pluto’s apparent motion. The 27 arc seconds is approximately 1/60th the width of a full Moon. So, from one night to the next, TNOs can travel as much as 100 pixels across the field of view of the DES survey detectors since each pixel has a width of 0.27 arc seconds.

Composite Dark Energy Camera image of one of the sky regions that the collaboration will use to study supernovae, exploding stars that will help uncover the nature of dark energy. The outlines of each of the 62 charge-coupled devices can be seen. This picture spans 2 degrees across on the sky and contains 520 megapixels. (Credit: Fermilab)
Composite Dark Energy Camera image of one of the sky regions that the collaboration will use to study supernovae, exploding stars that will help uncover the nature of dark energy. The outlines of each of the 62 charge-coupled devices can be seen. This picture spans 2 degrees across on the sky and contains 520 megapixels. (Credit: Fermilab)

The scientific sensor array, DECam, is located at Cerro Tololo Inter-American Observatory (CTIO) in Chile utilizing the 4-meter (13 feet) diameter Victor M. Blanco Telescope. It is an array of 62 2048×4096 pixel back-illuminated CCDs totaling 520 megapixels, and altogether the camera weighs 20 tons.

A simple plot of the orbit of one of sixteen TNOs discovered by DES observatrions. (Credit: Dark Energy Detectives)
A simple plot of the orbit of one of sixteen TNOs discovered by DES observations. (Credit: Dark Energy Detectives)

With a little over 2 years of observations, the young astronomers stated, “Our analysis revealed sixteen previously unknown outer solar system objects, including one Neptune Trojan, several objects in mean motion resonances with Neptune, and a distant scattered disk object whose 1200-year orbital period is among the 50 longest known.”

Object 2013 TV158 is one of the objects discovered by Carleton College and University of Michigan team. Observed more than a dozen times over 10 months, the animated gif shows two image frames from August, 2014 taken two hours apart. 2013 TV158 takes 1200 years to orbit the Sun and is likely a few hundred kilometers across (about the size of the Grand Canyon. (Credit: Dark Energy Detectives)
Object 2013 TV158 is one of the objects discovered by the Carleton College and University of Michigan team. Observed more than a dozen times over 10 months, the animated gif shows two image frames from August 2014 taken two hours apart. 2013 TV158 takes 1200 years to orbit the Sun and is likely a few hundred kilometers across – about the size of the Grand Canyon. (Credit: Dark Energy Detectives)

“So far we’ve examined less than one percent of the area that DES will eventually cover,” says Dr. Gerdes. “No other survey has searched for TNOs with this combination of area and depth. We could discover something really unusual.”

Illustration of colour distribution of the trans-Neptunian objects. The horizontal axis represents the difference in intensity between visual (green & yellow) and blue of the object while the vertical is the difference between visual and red. The distribution indicates how TNOs share a common origin and physical makeup as well as common weathering in space. Yellow objects serve as reference: Neptune's moon Triton, Saturn's moon Phoebe, centaur Pholus, and the planet Mars. The objects color represents the hue of the object. The size of the objects are relative where the larger objects are more accurate estimates and smaller objects are simply based on absolute magnitude. (Credit: Wikimedia, Eurocommuter)
Illustration of color distribution of the trans-Neptunian objects. The horizontal axis represents the difference in intensity between visual (green & yellow) and blue of the object, while the vertical axis is the difference between visual and red. The distribution indicates how TNOs share a common origin and physical makeup, as well as common weathering in space. Yellow objects serve as reference: Neptune’s moon Triton, Saturn’s moon Phoebe, centaur Pholus, and the planet Mars. The object’s color represents the hue of the object. The size of the objects are relative – the larger objects are more accurate estimates, while smaller objects are simply based on absolute magnitude. (Credit: Wikimedia, Eurocommuter)

What does it all mean? It is further confirmation that the outer Solar System is chock-full of rocky-icy small bodies. There are other examples of recent discoveries, such as the search for a TNO for the New Horizons mission. As New Horizons has been approaching Pluto, the team turned to the Hubble space telescope to find a TNO to flyby after the dwarf planet. Hubble made short shrift of the work, finding three that the probe could reach. However, the demand for Hubble time does not allow long term searches for TNOs. A survey such as DES will serve to uncover many thousands of more objects in the outer Solar System. As Dr. Michael Brown of Caltech has stated, there is a fair likelihood that a Mars or Earth-sized object will be discovered beyond Neptune in the Oort Cloud.

References:
Observation of new trans-Neptunian Objects in the Dark Energy Survey Supernova Fields
Undergraduate Researchers Discover New Trans-Neptunian Objects
Dark Sky Detectives

For more details on the Dark Energy Survey: DES Website

Posted on by Tim Reyes

2015: NASA’s Year of the Dwarf Planet

Two spacecraft, Dawn and New Horizon will reach their final objectives in 2015 - Dwarf Planets - Ceres and Pluto. (Credit: NASA, Illustration - T.Reyes)

Together, the space probes Dawn and New Horizons have been in flight for a collective 17 years. One remained close to home and the other departed to parts of the Solar System of which little is known. They now share a common destination in the same year: dwarf planets.

At the time of these NASA probes’ departures, Ceres had just lost its designation as the largest asteroid in our Solar System. Pluto was the ninth planet. Both probes now stand to deliver measures of new data and insight that could spearhead yet another revision of the definition of planet.

A comparison of the trajectories of New Horizon (left) and the Dawn missions (right). (Credit: NASA/JPL, SWRI, Composite- T.Reyes)
A comparison of the trajectories of New Horizons (left) and the Dawn missions (right). (Credit: NASA/JPL, SWRI, Composite- T.Reyes)

Certainly, NASA’s Year of the Dwarf Planet is an unofficial designation and NASA representatives would be quick to emphasize another dozen or more missions that are of importance during the year 2015. However, these two missions could determine the fate of billions or more small bodies just within our galaxy, the Milky Way.

If Ceres and Pluto are studied up close – mission success is never a sure thing – then what is observed could lead to a new, more certain and accepted definition of planet, dwarf planet, and possibly other new definitions.

The New Horizons mission became the first mission of NASA’s New Frontiers program, beginning development in 2001. The probe was launched on January 19, 2006, atop an Atlas V 551 (5 solid rocket boosters plus a third stage). Utilizing more compact and lightweight electronics than its predecessors to the outer planets – Pioneer 10 & 11, and Voyager 1 & 2 – the combination of reduced weight, a powerful launch vehicle, plus a gravity assist from Jupiter has lead to a nine year journey. On December 6, 2014, New Horizons was taken out of hibernation for the last time and now remains powered on until the Pluto encounter.

This "movie" of Pluto and its largest moon, Charon b yNASA's New Horizons spacecraft taken in July 2014 clearly shows that the barycenter -center of mass of the two bodies - resides outside (between) both bodies. The 12 images that make up the movie were taken by the spacecraft’s best telescopic camera – the Long Range Reconnaissance Imager (LORRI) – at distances ranging from about 267 million to 262 million miles (429 million to 422 million kilometers). Charon is orbiting approximately 11,200 miles (about 18,000 kilometers) above Pluto's surface. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)
This “movie” of Pluto and its largest moon, Charon, by NASA’s New Horizons spacecraft taken in July 2014 clearly shows that the barycenter – the center of mass of the two bodies – resides outside (between) both bodies. The 12 images that make up the movie were taken by the spacecraft’s best telescopic camera – the Long Range Reconnaissance Imager (LORRI) – at distances ranging from about 267 million to 262 million miles (429 million to 422 million kilometers). Charon is orbiting approximately 11,200 miles (about 18,000 kilometers) above Pluto’s surface. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

The arrival date of New Horizon is July 14, 2015. A telescope called the Long Range Reconnaissance Imager (LORRI) has permitted the commencement of observations while still over 240 million kilometers (150 million miles) from Pluto. The first stellar-like images were taken while still in the Asteroid belt in 2006.

Pluto was once the ninth planet of the Solar System. From its discovery in 1930 by Clyde Tombaugh until 2006, it maintained this status. In that latter year, the International Astronomical Union undertook a debate and then a membership vote that redefined what a planet is. The change occurred 8 months after New Horizons’ launch. There were some upset mission scientists, foremost of which was the principal investigator, Dr. Alan Stern, from the Southwest Research Institute in San Antonio, Texas. In a sense, the rug had been pulled from under them.

A gentleman’s battle ensued between opposing protagonists Dr. Stern and Dr. Michael Brown from Caltech. In 2001, Dr. Brown’s research team began to discover Kuiper belt objects (Trans-Neptunian objects) that rivaled the size of Pluto. Pluto suddenly appeared to be one of many small bodies that could likely number in the trillions within just one galaxy – ours. According to Dr. Brown, there could be as many as 200 objects in our Solar System similar to Pluto that, under the old definition, could be defined as planets. Dr. Brown’s work was the straw that broke the camel’s back – that is, it led to the redefinition of planet, and the native of Huntsville, Alabama, went on to write a popular book, How I Killed Pluto and Why It Had It Coming.

Dr. Stern’s story involving Pluto and planetary research is a longer and more circuitous one. Stern was the Executive Director of the Southwest Research Institute’s Space Science and Engineering Division and then accepted the position of Associate Administrator of NASA’s Science Mission Directorate in 2007. Clearly, after a nine year journey, Stern is now fully committed to New Horizons’ close encounter. More descriptions of the two protagonists of the Pluto debate will be included in a follow on story.

Artist’s concept depicting the Dawn spacecraft thrusting with its ion propulsion system as it travels from Vesta (lower right) to Ceres (upper left). The galaxies in the background are part of the Virgo supercluster. Dawn, Vesta and Ceres are currently in the constellation Virgo from the perspective of viewers on Earth. (Image credit: NASA/JPL)
Artist’s concept depicting the Dawn spacecraft thrusting with its ion propulsion system as it travels from Vesta (lower right) to Ceres (upper left). The galaxies in the background are part of the Virgo supercluster. Dawn, Vesta, and Ceres are currently in the constellation Virgo from the perspective of viewers on Earth. (Image credit: NASA/JPL)

The JPL and Orbital Science Corporation developed Dawn space probe began its journey to the main asteroid belt on September 27, 2007. It has used gravity assists and flew by the planet Mars. Dawn spent 14 months surveying Vesta, the 4th largest asteroid of the main belt (assuming Ceres is still considered the largest). While New Horizons has traveled over 30 Astronomical Units (A.U.) – 30 times the distance from the Earth to the Sun – Dawn has remained closer and required reaching a little over 2 A.U. to reach Vesta and now 3 A.U. to reach Ceres.

The Dawn mission had the clear objective of rendezvous and achieving orbit with two asteroids in the main belt between Mars and Jupiter. Dawn was also sent packing the next generation of Ion Propulsion. It has proven its effectiveness very well, having used ion propulsion for the first time to achieve an orbit. Pretty simple, right? Not so fast.

As Dawn was passing critical design reviews during development, the redefinition of planet lofted its second objective – the asteroid 1 Ceres – to a new status. While Pluto was demoted, Ceres was promoted from its scrappy status of biggest of the asteroids – the debris, the leftovers of our solar system’s development – to dwarf planet. Even 4 Vesta is now designated a proto-planet.

Artist rendition of Dawn spacecraft orbiting Vesta(Credit: NASA/JPL-Caltech)
Artist rendition of Dawn spacecraft orbiting Vesta. (Credit: NASA/JPL-Caltech)

So now the stage is set. Dawn will arrive first at a dwarf planet – Ceres – in April. With a small, low gravity body and ion propulsion, the arrival is slow and cautious. If the two missions fair well and achieve their goals, 2015 is likely to become a pivotal year in the debate over the classification of non-stellar objects throughout the universe.

Just days ago, at the American Geophysical Union Conference in San Francisco, Dr. Stern and team described the status and more details of the goals of New Horizons. Since arriving, more moons of Pluto have been discovered. There is the potential that faint rings exist and Pluto may even harbor an interior ocean due to the tidal forces from its largest moon, Charon. And Dawn mission scientists have seen the prospects for Ceres’ change. Not just the status, the latest Hubble images of Ceres is showing bright spots which could be water ice deposits and could also harbor an internal ocean.

The Solar System is becoming a more crowded place. This picture shows the sizes of dwarf planets Pluto, Ceres, Eris, and Makemake as compared to Earth and Earth's Moon, here called "Luna." None of the distances between objects are to scale. (Credit: NASA)
The Solar System is becoming a more crowded place. This picture shows the sizes of dwarf planets Pluto, Ceres, Eris, and Makemake as compared to Earth and Earth’s Moon, here called “Luna.” None of the distances between objects are to scale. (Credit: NASA)

So other NASA missions notwithstanding, this is the year of the dwarf planet. NASA will provide Humanity with its first close encounters with the most numerous of small round – by their self-gravity – bodies in the Universe. They are now called dwarf planets but ask Dr. Stern and company, the public, and many other planetary scientists and you will discover that the jury is still out.

References:

JHU/APL New Horizons Mission Home Page

NASA Dawn Mission Home Page

Related Universe Today articles:

NASA’s New Horizons

NASA’s Dawn Mission