Pluto Spacecraft Gets Brain Transplant

Artist rendition of New Horizons in the Kuiper Belt. Credit: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)

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Still seven years away from its rendezvous with Pluto, the New Horizons spacecraft was awoken from hibernation for the second annual checkout of all systems. The spacecraft and its team back on Earth will also undergo three months of operations as the New Horizons will make observations of Uranus, Neptune, and Pluto. But the first order of business was uploading an upgraded version of the software that runs the spacecraft’s Command and Data Handling system. “Our ‘brain transplant’ was a success,” says New Horizons Principal Investigator Alan Stern. “The new software – which guides how New Horizons carries out commands and collects and stores data – is now on the spacecraft’s main computer and operating, over a billion miles from home!”

The mission ops team at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, radioed the software load and the commands to start it earlier this week through NASA’s Deep Space Network of antennas to the spacecraft, now just more than 1.01 billion miles (1.62 billion kilometers) from Earth. In the next 10 days the team will beam up additional new software for both the spacecraft’s Autonomy and Guidance and Control systems.

Space Science Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
Space Science Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

Alice Bowman, New Horizons mission operations manager at APL, says the spacecraft and its computers are healthy. “The new software fixes a few bugs and enhances the way these systems operate, based on what we’ve learned in running the spacecraft in the nearly three years since launch,” she says. “They also configure the onboard systems to be ready to support the Pluto-Charon encounter rehearsals scheduled for next summer.”

New Horizons is more than 200 million miles beyond Saturn’s orbit and more than 11 astronomical units (1.02 billion miles) from the Sun, flying about a million miles per day toward Pluto. Annual Checkout 2 (ACO-2) continues through mid-December; follow its progress through frequent updates on the New Horizons Twitter page.

Source: New Horizons Press Release

Sun Orbit

Position of the Sun in the Milky Way. Image credit: NASA

Everything’s orbiting something it seems. The Moon goes around the Earth, and the Earth orbits the Sun. But did you know that the Sun orbits the Milky Way galaxy?

Astronomers have calculated that it takes the Sun 226 million years to completely orbit around the center of the Milky Way. In other words, that last time that the Sun was in its current position in space around the Milky Way, dinosaurs ruled the Earth. in fact, this Sun orbit has only happened 20.4 times since the Sun itself formed 4.6 billion years ago.

Since the Sun is 26,000 light-years from the center of the Milky Way, it has to travel at an astonishing speed of 782,000 km/hour in a circular orbit around the Milky Way center. Just for comparison, the Earth is rotating at a speed of 1,770 km/h, and it’s moving at a speed of 108,000 km/h around the Sun.

It’s estimated that the Sun will continue fusing hydrogen for another 7 billon years or so. In other words, it only has another 31 orbits it can make before it runs out of fuel.

Are you interested in more articles about the Sun? We have written plenty for Universe Today. Here’s an article that shows how some stars take an erratic journey around the Milky Way, and another article about a ring of stars orbiting the Milky Way.

Here’s an article that describes the process astronomers used to determine the orbit around the Milky Way.

We have recorded an episode of Astronomy Cast just about the Sun called The Sun, Spots and All.

References:
NASA Imagine the Universe!
NASA Spacemath
NASA Solar System Exploration Page

Got a Green Idea? Win $25,000

From the people that brought you the X PRIZE and the Google Lunar X PRIZE comes something new that’s a little more down to Earth. However they also say it’s crazy. But if you’re handy with a video camera, care about the environment, and are interested in winning a nice chunk of spare change, this might be up your alley. The $25,000 “What’s your crazy green idea?” Video Contest was just announced, and the X PRIZE folks are looking to find out what crazy ideas are out there that could become the next big thing for the environoment. “Before something is a breakthrough, it’s a crazy idea,” they say, and the X PRIZE Foundation is looking for your crazy green ideas to become the next X PRIZE. Here’s a video for more information:

Here are the rules:

1. Submit a 2 minute video to this group by October 31, 2008 explaining what you think should be the next Energy and Environment X PRIZE. Here’s the link.

2. The three most viable ideas will be posted on the X PRIZE website on November 15.

3. The public will be given two weeks to vote for the winner on the same site. The most creative, revolutionary idea and video will receive $25,000 and it could become the next great X PRIZE.

Be sure that your video answers the following questions:

1. What is the Grand Challenge or world-wide problem that you are trying to solve?
2. What is the specific prize idea (goal, rules, judging criteria)?
3. How will this prize lead to benefits for humanity?

Good luck!

Source: The Launch Pad

Sun and Earth

Sun with a huge coronal mass ejection. Image credit: NASA

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We owe everything we have to the Sun. If it weren’t for the Sun, there’d be no life on Earth. The relationship between Sun and Earth has gone back for 4.6 billion years, and should last for another 7 billion years or so.

As you probably know, the Sun is just a giant sphere of gas. At the core of the Sun, huge quantities of hydrogen are squished together in the intense pressure and temperature of this extreme environment. Hydrogen is converted to helium, and this reaction releases a tremendous amount of energy.

How much energy? Astronomers calculate that there are 600 million tons of hydrogen fused every second. 4 million tons of matter is converted to pure energy every second. This releases 3.86×1026 joules of energy every second. Although most of this energy heads off into space, plenty still falls onto the Earth. In fact, there’s enough energy coming from the Sun to deposit 342 Watts of energy onto every square meter of the Earth (averaged over the year, over the whole planet).

From our perspective, Sun and Earth go hand in hand. This energy from the Sun heats up the planet, preventing us from cooling down to near absolute zero temperatures of space. Our atmosphere traps the energy as heat, keeping the whole planet a nice comfortable temperature.

Plants have been soaking up this energy for millions of years. When you burn gasoline in your car, it comes from oil, which is energy from the Sun that planets have been storing for millions of years.

Sun and Earth are locked in a gravitational dance as well. The mass of the Sun is 2 × 1030 kilograms. This is enough to reach out across space and keep the Earth (and the rest of the planets) locked in orbit around it. We even experience tides from the gravity of the Sun.

Were you wondering how far away the Earth is from the Sun? And the Sun isn’t always trying to help us. Sometimes it’s throwing monster flares at us as well.

Here’s NASA’s Solar System Exploration Guide on the Sun. And here’s the homepage for NASA’s STEREO mission, which is taking amazing pictures and videos of the Sun.

We have recorded an episode of Astronomy Cast just about the Sun called The Sun, Spots and All.

References:
NASA Sun Earth Day
NASA Cosmicopia: Sun

Weekend SkyWatcher’s Forecast – September 12 -14, 2008

Greetings, fellow SkyWatchers! It’s big… It’s bright. It’s undeniably the Moon. So what are we going to do this weekend? Why, study of course! We’ll take a look at some history, some mystery and even some cool variability that can be studied without any special equipment. Are you ready to journey into the night?

Friday, September 12, 2008 – Arthur Auwers was born today in 1838. His life’s work included unifying the world’s observational catalogs. He specialized in astrometry, making very precise measurements of stellar positions and motions and he also calculated the orbits of Sirius and Procyon long before their companions were discovered. Auwers also directed expeditions to measure the transits of Venus and began a project to unify the all available sky charts, an interest that began with his catalog of nebulae which he published in 1862. There’s even a lunar crater named for him!

Also today, in 1959, the USSR’s Luna 2 became the first manmade object to hit the moon. It was the first spacecraft to reach the surface of the Moon, and it impacted the lunar surface west of Mare Serenitatis near the craters Aristides, Archimedes, and Autolycus. Scientifically, Luna 2 is most famous for confirming the earlier detection of the solar wind by Luna 1. However, it’s most famous for what it did after it launched! When it separated from its third stage, the spacecraft released a bright orange cloud of sodium gas, which aided in spacecraft tracking and acted as an experiment on the behavior of gas in space. Can you imagine the sight? Today also celebrates the 1966 Gemini 11 launch – the highest Earth orbit ever reached by an American manned spacecraft (1374 kilometer altitude).

Tonight our primary lunar study is crater Kepler. Look for it as a bright point, slightly north of lunar center near the terminator. Its home is the Oceanus Procellarum – a sprawling dark mare composed primarily of minerals of low reflectivity (low albedo), such as iron and magnesium. Bright, young Kepler will display a wonderfully developed ray system. The crater rim is very bright, consisting mostly of a pale rock called anorthosite. The “lines” extending from Kepler are fragments that were splashed out and flung across the lunar surface when the impact occurred. The region is also home to features known as “domes” – seen between the crater and the Carpathian Mountains. So unique are Kepler’s geological formations that it became the first crater mapped by U.S. Geological Survey in 1962.

Saturday, September 13, 2008 – Today in 1922, the highest air temperature ever recorded on the surface of the Earth occurred. The measurement, taken in Libya, burned in at a blistering 136° F (58° C) – but did you know that the temperatures in the sunlight on the Moon double that? If you think the surface of the Moon is a bit too warm for comfort, then know that surface temperatures on the closest planet to the Sun can reach up to 800° F (430° C) at the equator during the day! As odd as it may sound, and even as close to the Sun as Mercury is, it could very well have ice deposits hidden below the surface at its poles.

Get out your telescope, because tonight we’re going to have a look at a lunar feature that goes beyond simply incredible – it’s downright weird. Start your journey by identifying Kepler, and head due west across Oceanus Procellarum until you encounter the bright ring of crater Reiner. Spanning 30 kilometers, this crater isn’t anything showy…just shallow-looking walls with a little hummock in the center. But, look further west and a little more north for an anomaly – Reiner Gamma.

Well, it’s bright. It’s slightly eye-shaped. But what exactly is it? Having no appreciable elevation or depth, Reiner Gamma could very well be an extremely young feature caused by a comet. Only three other such features are known to exist – two on the lunar far side and one on Mercury. They are high albedo surface deposits with magnetic properties. Unlike a lunar ray, consisting of material ejected from below the surface, Reiner Gamma can be spotted during the daylight hours – when ray systems disappear. And, unlike other lunar formations, it never casts a shadow.

Reiner Gamma is also a magnetic deviation on a barren world that has no magnetic field, so how did it form? Many ideas have been proposed, such as solar storms, volcanic activity, or even seismic waves. But the best explanation? It is the result of a cometary strike. Evidence exists that a split-nucleus comet, or cometary fragments, once impacted the area, and the swirl of gases from the high-velocity debris may have somehow changed the regolith. On the other hand, ejecta from such an impact could have formed around a magnetic “hot spot,” much like a magnet attracts iron filings.

No matter which theory is correct, the simple act of viewing Reiner Gamma and realizing it is different from all other features on the Moon’s Earth-facing side makes this journey well worth the time!

Sunday, September 14 – With a nearly Full Moon, skies are light-trashed tonight, so if you’d like to visit another object that only requires your eyes, then look no further than Eta Aquilae (RA 19 52 28 37 Dec +01 00 20), about one fistwidth due south of Altair…

Discovered by Pigot in 1784, this Cepheid variable varies by over a magnitude in a period of 7.17644 days. During this time it will reach of maximum of magnitude 3.7, and then decline slowly over five days to a minimum of 4.5… Yet it only takes two days to brighten again! This period of expansion and contraction makes Eta unique. To help gauge these changes, compare Eta to Beta on Altair’s same southeast side. When Eta is at maximum, it will about equal Beta in brightness.

Wishing you clear skies and a super weekend!!

This week’s awesome images are Kepler Crater by Wes Higgins, Luna 2 courtesy of NASA, Reiner Gamma from the Clementine Lunar Browser and Eta Aquilae – Credit: Palomar Observatory, courtesy of Caltech. Many thanks!

Phoenix Spies – and Feels – Dust Devils

A dust devil dances in the distance from the Phoenix lander. Credit: NASA/JPL/Caltech/U of AZ

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Not only has the Phoenix Mars Lander photographed several dust devils dancing across the arctic plain this week, but sensors that monitor various atmospheric conditions around the lander detected a dip in air pressure as one of the whirlwinds passed nearby. This is the first time dust devils have been detected in Phoenix images. Scientists believe the increasing difference between daytime high temperatures (about -30C) and night lows (around -90C) is the key to the formation of the dust devils. Click here to download a dust devil movie created from the images.

The Surface Stereo Imager camera on Phoenix took 29 images of the western and southwestern horizon on Sept. 8, during mid-day hours of the lander’s 104th Martian day. The next day, after the images had been transmitted to Earth, the Phoenix science team noticed a dust devil right away.

“It was a surprise to have a dust devil so visible that it stood with just the normal processing we do,” said Mark Lemmon of Texas A&M University, College Station, lead scientist for the stereo camera. “Once we saw a couple that way, we did some additional processing and found there are dust devils in 12 of the images.”

Another image of a dust devil from Phoenix.  Credit:  NASA/JPL/Caltech/U of AZ
Another image of a dust devil from Phoenix. Credit: NASA/JPL/Caltech/U of AZ

At least six different dust devils appear in the images, some of them in more than one image. They range in diameter from about 2 meters (7 feet) to about 5 meters (16 feet).

The Phoenix team is not worried about any damage to the spacecraft from these swirling winds. “With the thin atmosphere on Mars, the wind loads we might experience from dust devil winds are well within the design of the vehicle,” said Ed Sedivy, Phoenix program manager at Lockheed Martin Space Systems Company, Denver, which made the spacecraft. “The lander is very rigid with the exception of the solar arrays, which once deployed, latched into position and became a tension structure.”

Phoenix monitors air pressure every day, and on the same day the camera saw dust devils, the pressure meter recorded a sharper dip than ever before. The change was still less than the daily change in air pressure from daytime to nighttime, but over a much shorter time.

“Throughout the mission, we have been detecting vortex structures that lower the pressure for 20 to 30 seconds during the middle part of the day,” said Peter Taylor of York University, Toronto, Canada, a member of the Phoenix science team. “In the last few weeks, we’ve seen the intensity increasing, and now these vortices appear to have become strong enough to pick up dust.”

The same day as the dust devils were seen, the photographed swinging of Phoenix’s telltale wind gauge indicated wind speeds exceeding 5 meters per second (11 miles per hour). Download a movie of the telltail wind gauge.

Images from spacecraft orbiting Mars had previously indicated that dust devils exist in the region where Phoenix landed.

“We expected dust devils, but we are not sure how frequently,” said Phoenix Project Scientist Leslie Tamppari of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “It could be they are rare and Phoenix got lucky. We’ll keep looking for dust devils at the Phoenix site to see if they are common or not.”

The dust devils that Phoenix has observed so far are much smaller than dust devils that NASA’s Mars Exploration Rover Spirit has photographed much closer to the equator.

Source: Phoenix news site.

Satellite, ISS Images of Hurricane Ike

Hurricane Ike is bearing down on the US gulf coast, and even before landfall, is causing problems. Nearly 1 million people along the Texas coast have been ordered to evacuate, the other 3 million people in the Houston metro area have been asked not to leave, in hopes of avoiding the panic of three years ago, when evacuations ordered in advance of Hurricane Rita sent millions onto highways causing traffic jams and deadly accidents. The airports in Houston will close tomorrow, and NASA’s Johnson Space Center closed today.

Image of Ike taken from the ISS. Credit:  NASA
Image of Ike taken from the ISS. Credit: NASA
Astronauts on board the International Space Station had this view of Ike from their orbital perch 220 statute miles above the Earth. (See below for a larger, close-up image.) Mission managers for the ISS have taken up residence in a hotel far inland, armed with laptops and a secure high speed internet connection in order to maintain contact with the orbiting space station. Ike is currently a Category 2 hurricane according to the National Hurricane Center, but forecasters were predicting that Ike might reach Category 3 strength in the warm waters of the Gulf prior to its projected landfall on the central Texas coastline.

TRMM (Tropical Rainfall Measuring Mission) spacecraft observed this view of Hurricane Ike on September 10, 2008 at 1745 UTC. The storm was a category 2 hurricane with sustained winds of 85 knots (97.75 mph) and a pressure reading of 958 millibars. At this time, the storm has two nearby well-defined wind maxima of roughly equal strength. There is a 17 km tower in the outer eye.

Click here for an animation from the TRMM spacecraft data.

The astronauts on board the International Space Station had this incredible view of the hurricane as it approached the Gulf Coast.

Ike was a Category 4 storm before its passage over Cuba stripped it of some of its power. It re-emerged in the Gulf of Mexico as a Category 1 storm and re-strengthened.

As of 10:00 a.m., Sept. 11, hurricane warnings are up from Morgan City Louisiana to Baffin Bay, Texas. Hurricane conditions could reach the coast within the warning area by late Friday, Sept. 12.

Ike is a Category 2 hurricane with maximum sustained winds near 100 mph. He is forecast to strengthen to a Category 3 storm before reaching the Texas coastline. Ike is moving west-northwest near 10 mph and will be near the coast late on Sept. 12, however, because Ike is large, tropical storm force winds will be felt far in advance.

Sources: NASA’s ISS Page, NASA Earth Observatory Page, The Weather Channel. Here are even more hurricane photos and hurricane images.

Ten Interesting Facts About the Sun

The Sun as viewed by the Solar and Heliospheric Observatory (NASA/SOHO)

Think you know everything there is to know about the Sun? Think again. Here are 10 facts about the Sun, collected in no particular order. Some you might already know, and others will be totally new to you.

1. The Sun is the Solar System
We live on the planet, so we think it’s an equal member of the Solar System. But that couldn’t be further from the truth. The reality is that the mass of the Sun accounts for 99.8% of the mass of the Solar System. And most of that final 0.2% comes from Jupiter. So the mass of the Earth is a fraction of a fraction of the mass of the Solar System. Really, we barely exist.

2. And the Sun is mostly hydrogen and helium
If you could take apart the Sun and pile up its different elements, you’d find that 74% of its mass comes from hydrogen. with 24% helium. The remaining 2% is includes trace amounts of iron, nickel, oxygen, and all the other elements we have in the Solar System. In other words, the Solar System is mostly made of hydrogen.

3. The Sun is pretty bright.
We know of some amazingly large and bright stars, like Eta Carina and Betelgeuse. But they’re incredibly far away. Our own Sun is a relatively bright star. If you could take the 50 closest stars within 17 light-years of the Earth, the Sun would be the 4th brightest star in absolute terms. Not bad at all.

4. The Sun is huge, but tiny
With a diameter of 109 times the size the Earth, the Sun makes a really big sphere. You could fit 1.3 million Earths inside the Sun. Or you could flatten out 11,990 Earths to cover the surface of the Sun. That’s big, but there are some much bigger stars out there. For example, the biggest star that we know of would almost reach Saturn if it were placed inside the Solar System.

5. The Sun is middle aged
Astronomers think that the Sun (and the planets) formed from the solar nebula about 4.59 billion years ago. The Sun is in the main sequence stage right now, slowly using up its hydrogen fuel. But at some point, in about 5 billion years from now, the Sun will enter the red giant phase, where it swells up to consume the inner planets – including Earth (probably). It will slough off its outer layers, and then shrink back down to a relatively tiny white dwarf.

6. The Sun has layers
The Sun looks like a burning ball of fire, but it actually has an internal structure. The visible surface we can see is called the photosphere, and heats up to a temperature of about 6,000 degrees Kelvin. Beneath that is the convective zone, where heat moves slowly from the inner Sun to the surface, and cooled material falls back down in columns. This region starts at 70% of the radius of the Sun. Beneath the convection zone is the radiative zone. In this zone, heat can only travel through radiation. The core of the Sun extends from the center of the Sun to a distance of 0.2 solar radii. This is where temperatures reach 13.6 million degrees Kelvin, and molecules of hydrogen are fused into helium.

7. The Sun is heating up, and will kill all life on Earth
It feels like the Sun has been around forever, unchanging, but that’s not true. The Sun is actually slowly heating up. It’s becoming 10% more luminous every billion years. In fact, within just a billion years, the heat from the Sun will be so intense that liquid water won’t exist on the surface of the Earth. Life on Earth as we know it will be gone forever. Bacteria might still live on underground, but the surface of the planet will be scorched and uninhabited. It’ll take another 7 billion years for the Sun to reach its red giant phase before it actually expands to the point that it engulfs the Earth and destroys the entire planet.

8. Different parts of the Sun rotate at different speeds
Unlike the planets, the Sun is great big sphere of hydrogen gas. Because of this, different parts of the Sun rotate at different speeds. You can see how fast the surface is rotating by tracking the movement of sunspots across the surface. Regions at the equator take 25 days to complete one rotation, while features at the poles can take 36 days. And the inside of the Sun seems to take about 27 days.

9. The outer atmosphere is hotter than the surface
The surface of the Sun reaches temperatures of 6,000 Kelvin. But this is actually much less than the Sun’s atmosphere. Above the surface of the Sun is a region of the atmosphere called the chromosphere, where temperatures can reach 100,000 K. But that’s nothing. There’s an even more distant region called the corona, which extends to a volume even larger than the Sun itself. Temperatures in the corona can reach 1 million K.

10. There are spacecraft observing the Sun right now.
The most famous spacecraft sent to observe the Sun is the Solar and Heliospheric Observatory, built by NASA and ESA, and launched in December, 1995. SOHO has been continuously observing the Sun since then, and sent back countless images. A more recent mission is NASA’s STEREO spacecraft. This was actually two spacecraft, launched in October 2006. These twin spacecraft were designed to watch the same activity on the Sun from two different vantage points, to give a 3-D perspective of the Sun’s activity, and allow astronomers to better predict space weather.

We have recorded an episode of Astronomy Cast all about the Sun called The Sun, Spots and All.

References:
NASA Science
NASA SOHO
NASA Stereo

ESA Needs a Name for Next ISS Mission

ESA Astronaut Frank DeWinne on board the ISS. Credit: ESA

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The European Space Agency needs a bang-up, attention-grabbing moniker for the next long duration European mission to the International Space Station, and they are holding a competition for the public to submit a suitable name. In May 2009, ESA astronaut Frank De Winne, of Belgium will fly to the ISS for a six month mission. ESA is holding a competition to find a name for the mission. Have any great ideas? Here are the parameters for the competition:

The name has to reflect the following aspects:

1. Europe is exploring space, and humans are explorers by nature. Europe has a legacy in exploring Earth and will live up to the expectations in exploring Space.

2. Europe has its own Columbus laboratory permanently in space on the ISS. Europe uses its Columbus laboratory on the ISS for science, technology and education for the benefit of life on Earth.

3. From space our planet looks blue because of the water. Water is the basis of life; Clean water is the basis for healthy life of all humans on Earth.

Wow, that’s a tough set of parameters. Now, here’s a few rules: (for the full rules see HERE)

1. The competition is open to all citizens of the ESA Member States (sorry US and Canada folks, you’re out of luck on this one.)

2. The proposals have to arrive in the [email protected] mailbox the latest by 18:00 CEST, 15 October 2008.

3. The proposal should be maximum of one page, with 12 pt single spacing

4. The name should be a word (or a short combination of words), not a personal name (unless it is a mythological name which has a commonly known symbolic meaning).

Again, here’s the full rules. Have fun and go for it!

Source: ESA

Hunting for Meteorites at the Bottom of the World

Team members gather to inspect and collect a meteorite being placed in a Teflon bag. Photo credit: M. Keiding, 2007

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Antarctica’s distinctive, unforgiving environment is truly unique. But add to that setting the otherworldly task of looking for meteorites — bits and pieces from the far reaches of our solar system that are strewn about Antarctica’s icy surface,– and Earth’s southern-most continent can provide a truly unparalleled scientific experience. “I had the privilege to explore a part of the world that few people get to,” said Dr. Lucy McFadden, a research professor in the astronomy department at the University of Maryland, College Park. She also is a scientist in the education and public outreach area for NASA’s Dawn mission that is traveling to study the asteroids Ceres and Vesta. McFadden had the opportunity to travel to Antarctica and spend over six weeks hunting for meteorites, specifically looking for meteorites from Ceres and Vesta. She shared her experiences recently in an online “webinar,” answering questions about her journey. “I love sharing my adventures,” she said. “My excitement about exploring the solar system was renewed because I had the opportunity to explore Earth as a planet.”

Although meteorites fall uniformly all over the Earth –estimates are between 30-80 tons a year, — most are in the form of dust. For the bigger rock-sized pieces, many fall in the ocean and those that fall on land can be buried by shifting terrain, broken down by chemical weathering, or are easily confused with Earth rocks. But Antarctica’s blue ice sheets are clear and barren, making it easy to spy a dark rock that’s likely a sample from space.

Aerial view of Antarctica.  Photo credit: L. McFadden 2008
Aerial view of Antarctica. Photo credit: L. McFadden 2008

However, there’s another reason Antarctica is such a great place to look for meteorites. “There’s something special about Antarctica. Meteorites collect in certain areas there,” McFadden said. “The ice sheets are always moving, and the meteorites move with them. But the rocks get trapped by the barriers of the mountains, and that’s where the meteorites are found. Once you get a meteorite up against a barrier, the constant blowing of the polar winds ablates the ice, and rocks effectively come to the surface.” Over periods of tens or hundreds of thousands of years, very significant concentrations can build up in these areas.

Since 1976, the U.S. National Science Foundation has supported an annual search for meteorites during the Antarctic summer, through a program called ANSMET, the Antarctic Search for Meteorites. McFadden was part of an eight-member meteorite hunting team in November 2007 to January 2008.

McMurdo Station. Photo credit: L. McFadden, 2008
McMurdo Station. Photo credit: L. McFadden, 2008

A C-17 cargo plane brought the team to Antarctica’s McMurdo Station. But one doesn’t just go out and start hunting for rocks without instructions on how to survive Antarctica’s harsh environment. The team underwent a week of training that included lessons on proper clothing. “I had to learn which coat to put on when, which hat and gloves to wear and be sure to have my boots on,” said McFadden. “It brought me back to kindergarten.” Also, learning snowmobile operation and repair is a must, as that would be their mode of transportation during their expeditions. “We were trained how to stay away from the crevasses in the ice and trained for rescue in case someone fell in,” she said.

A plane then brought the team, the snowmobiles, fuel and gear to their field site on the Miller Range to set up camp. They erected tents – their homes for six weeks, and had to chip ice to get water for drinking and cooking. Typical daytime temperature was about 20 degrees Fahrenheit (-6 C) when there wasn’t a storm.

High winds at field camp.  Photo credit: L. McFadden, 2007
High winds at field camp. Photo credit: L. McFadden, 2007

At 70 degrees south latitude, the Antarctic summer sun never set. But the surroundings were desolate, to say the least. The region is mountainous, but constantly snow and ice covered. “I felt a sense of vulnerability of us humans,” McFadden said. “This is not a hospitable environment.” She also worried about the possibility of getting lost in the barren landscape with few landmarks. But with them was a seasoned, expert guide, John Schutt.

So what’s the trick of finding meteorites in Antarctica? “We practiced around the camp first, and walked up to all the rocks in the area,” said McFadden. “There are other rocks on the ground from rockslides from the mountains, so you have to learn what the local rocks look like.” Dr. Ralph Harvey, the head of the ANSMET program taught the team the art of meteorite hunting.

“When you find a field of rocks, you have to look closely and separate out the regular rocks from meteorites,” McFadden said. Most meteorites are black because they have a fusion crust: a thin glassy rind that forms on meteorites when they are coming through the atmosphere. The friction heats them up and the outside of the meteorite melts just a little.

“We looked at each rock,” said McFadden. “If we thought we found a meteorite, we waved our arms and everyone would come over and look. If we determined it was a meteorite, we would pick it up with tongs and put it in a Teflon bag and mark it. Then we planted a flag where we found a meteorite. It was very satisfying to look back where we’d been and see all the flags.”

Flags marking meteorite finds.  credit: M. Keiding and ANSMET 2007-2008.
Flags marking meteorite finds. credit: M. Keiding and ANSMET 2007-2008.

They followed a certain procedure to make notes on each meteorite, take pictures, note the position of each sample with a Global Positioning System monitor, and then wrap the meteorites in a certain way and put them in backpacks. “It was a big process to catalogue and account for all of them,” McFadden said.

At the end of the day they collected all the rocks from the backpacks and put them in bags in a specialized container to keep them cold. This would avoid contamination from any snow that might be attached to the rocks, until they are brought to Johnson Space Center where they are catalogued and then distributed to scientists around the world.

A large meteorite found by the team. Photo credit: ANSMET 2007 Case Western Reserve University
A large meteorite found by the team. Photo credit: ANSMET 2007 Case Western Reserve University

Each of the meteorites tells a story about the processes of the early solar system. Scientists who study meteorites can find clues to the conditions as our solar system evolved, and find out more about the asteroids, moons and planets the meteorites originate from. Meteorites represent a “free” sample return mission for scientists.

The team didn’t do any scientific analysis out in the field, just collected the samples for transport to the laboratories in Houston. But that doesn’t mean they didn’t examine the rocks!

The team found lots of carbonaceous chondrites with very irregular and jagged shapes, some that may have come from the Moon, and others with a green mineral called olivine that may have come from Mars. One meteorite found made the team think of the famous ALH 84001 meteorite found in the Allan Hills region of Antarctica, that made headlines in 1996 when it was announced that the meteorite may contain evidence for traces of life from Mars. “We wondered if this one meteorite was related to ALH 84001,” said McFadden. But the team won’t know the answer until geochemical analyses are performed.

As for her search for samples from Ceres and Vesta, McFadden said, “I think we might have been successful in finding samples from Vesta, but I was really interested in looking for samples from Ceres. However, I wasn’t really sure what I was looking for. As far as we know we don’t have samples from Ceres.”

Small meteorite. Photo credit: ANSMET 2007 Case Western Reserve University
Small meteorite. Photo credit: ANSMET 2007 Case Western Reserve University

How do scientists know a meteorite came from a specific asteroid? “The whole study of meteoritics addresses that through laboratory studies of many different attributes of rocks,” said McFadden. “We know we have rocks in our meteorite collection from Vesta because about one in every seven meteorites we find has characteristics, or spectral signature, that matches Vesta as viewed through a telescope. We look at Vesta and see a huge impact basin that the meteorites probably came from.”

But Ceres is a different matter. “We don’t know much about Ceres,” she said. “The spectral signature of Ceres doesn’t match anything we have in the meteorite collection. But maybe they’ll find one in the samples we brought back or eventually find one on a future expedition.”

Snowmobiles, the vehicle of choice for Antarctic meteorite hunting. Photo credit: L. McFadden, 2007
Snowmobiles, the vehicle of choice for Antarctic meteorite hunting. Photo credit: L. McFadden, 2007

With stormy periods when they had to huddle in their tents, McFadden’s team had 22 full days of meteorite searching, and eight half days. They went out at 9:00 am, returning at 5:00 pm. “We had six guys and two women,” said McFadden. It’s different for each expedition. We didn’t know each other before hand, but we worked well together. We had this common experience and we had to look out for each other. But it was also very lonely; there wasn’t that much opportunity to interact. We were exhausted each night.”

They did have opportunities for recreation such as skiing, playing games or reading books. One particularly nice day they made a couch from snow and sat outside for awhile. Planes occasionally brought re-supply of food, letters, and other supplies. They were in Antarctica for Christmas, so they decorated and had a potluck supper. “The isolation and cold weather got to us after awhile, but we loved our time out there,” McFadden said. “We looked forward to going home, but we had a tremendous experience. We all appreciated the beauty of Antarctica.”

Aerial view near McFadden's field camp in the Miller Range. Photo credit: M. Keiding, 2007
Aerial view near McFadden's field camp in the Miller Range. Photo credit: M. Keiding, 2007

Their expedition found 710 meteorites, some as small as a little finger nail (about 1.0 x 0.5 x 0.5 cm) 3a), and others about 8 pounds and too big to hold in one hand (about 25 cm x 15 cm x 12).
“We had good hunting,” she said. “It wasn’t a record. Some days we wanted to keep going, but our guide had to keep us in check and keep us safe. In that climate you do have to stop and take care of yourself.”

Over the more than 25 years of these expeditions, over 26,000 meteorites have been found, expanding the volume of extraterrestrial materials that can be studied here on Earth to provide a context for our remote sensing explorations out in the solar system, such as the Dawn mission. “My experience searching for meteorites inspired me to continue trying to understand the meteorites themselves and pair that with my exploration with the Dawn spacecraft that is searching out in the solar system,” said McFadden.

And now another team of scientists is preparing to return to Antarctica in November this year to continue the hunt.

Dr. Lucy McFadden, Dawn Co-Investigator and Education and Public Outreach (E/PO) lead Photo credit: M. Keiding, 2007
Dr. Lucy McFadden, Dawn Co-Investigator and Education and Public Outreach (E/PO) lead Photo credit: M. Keiding, 2007

McFadden responded to the question of why teams keep going back every year to look for meteorites. “There is the potential to find new types of meteorites. In 2006, they found a type of meteorite that had never been seen before. They believe it’s from another body in our solar system that was probably the size of the moon, but its isotopic signature is decidedly different from the moon or Mars. So we have indeed found evidence of planetesimals that are new to us that are out there in the asteroid belt. That’s very exciting and that keeps us going.”

More information:
McFadden’s article on the Dawn website.
McFadden’s video “webinar” presentation.

“Find a Meteorite” online activity
Dawn Mission website
Dawn Mission Education website