All posts by CCPetersen

ExoMars 2016 takes Next Step to the Red Planet

ExoMars Schiaparelli and TGO mating.
Schiaparelli being installed at the top of the ExoMars TGO. Credit: ESA–Stephane Corvaja, 2015


ExoMars: Europe’s Mission to Mars!

ExoMars is nearly ready to go! This mission is a “two-fer” being sent by the European Space Agency to the Red Planet.  The first part contains a Trace Gas Orbiter instrument mated to the Schiaparelli landing module. Schiaparelli will actually make a soft landing on the planet’s surface. This mission is actually a technology demonstrator — a “practice run” — for a followup 2018 ExoMars mission. That one will have a rover and a platform of science instruments to do studies of the surface and atmosphere.

The final adjustments to ExoMars 2016 are being made in Cannes, France. Then, the spacecraft heads to Baikonur for launch.  This first mission is scheduled to lift off on March 14th and has a launch window that extends to March 25th.

After a cruise of almost seven months, Schiaparelli  will separate from TGO on October 16,  2016. It will then enter the thin Martian atmosphere, descend and land on the surface at a region called Meridiani Planum. The landing is scheduled for October 19th. If all goes well, the lander will send a signal back to Earth via the TGO, telling controllers it arrived safely.

Schiaparelli is an entry, descent and landing demonstrator. It will test a number of technologies that should allow a controlled landing on Mars for the second mission in the series. The Trace Gas Orbiter will sample gases in Mars’ atmosphere and will serve as a data relay for the second mission, which will contain a rover and surface science platform.

The ExoMars mission is a joint endeavor with the Russian Roscosmos space agency, and is the first of a series of cooperative missions between Russia and ESA.

A Closeup Look at Enceladus

An Enchanting (and Frozen) World!


Closest Northern Views of Saturn's Moon Enceladus Saturnian SnowmanA Fractured Pole Craters Crowd the North NASA's Cassini spacecraft zoomed by Saturn's icy moon Enceladus on Oct. 14, 2015, capturing this stunning image of the moon's north pole. A companion view from the wide-angle camera (PIA20010) shows a zoomed out view of the same region for context. Image Credit: NASA/JPL-Caltech/Space Science Institute
NASA’s Cassini spacecraft zoomed by Saturn’s icy moon Enceladus on Oct. 14, 2015, capturing this stunning image of the moon’s north pole. A companion view from the wide-angle camera (PIA20010) shows a zoomed out view of the same region for context. Image Credit: NASA/JPL-Caltech/Space Science Institute

The NASA Cassini mission did a swooping close pass over the Saturnian moon Enceladus and is now returning amazing images of this water-rich moon. The image shown here is a zoom in of the north pole, showing cracked cratered ice. The whole moon is fractured like this. Not only that, but astronomers expected that the polar region would be cratered, and the images proved them right.

The October 14th flyby is not the last close encounter Cassini will have with Enceladus. On October 28th, the spacecraft will swoop to within 30 miles of the south polar region, and along the way, will pass through the spray of icy material jetting out from beneath the frozen surface. The spacecraft instruments will sample the chemistry of the extraterrestrial ocean beneath the ice, and mission team members are hoping the data from that flyby will provide evidence of how much hydrothermal activity is occurring in the moon’s ocean.

Cassini’s final close Enceladus flyby will take place on Dec. 19, when the spacecraft will measure the amount of heat coming from the moon’s interior. The flyby will be at an altitude of 3,106 miles (4,999 kilometers).

More News from Comet 67P

Details of the Comet’s Water-Ice Cycle

Illustrating the water-ice cycle at Comet 67P. Data: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; M.C. De Sanctis et al (2015); Comet: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0

Comet 67P/Churyumov-Gerasimenko is one of the most-studied comets in history because it has a spacecraft riding alongside it as it orbits the Sun.  Like all other comets, it is an icy chunk made of a mixture of water and other ices plus a healthy helping of dust grains.

When a comet gets close to the Sun in its orbit — a point called perihelion — sunlight warms the nucleus and causes the ices to go from a solid to a gaseous state. That’s called “sublimation” and is similar to what dry ice does if you leave it out exposed to the Sun.

The Rosetta mission has been studying this process at Comet 67P, and found that as the comet rotates, various parts of its surface are exposed to the Sun over a 12-hour period. As they warm, water ice sublimates, and the spacecraft detected that.

The data suggest that water ice on and a few centimeters below the surface sublimates when illuminated by sunlight, turning it into gas that then flows away from the comet. Then, as the comet rotates and the same region falls into darkness, the surface rapidly cools again.

However, the underlying layers remain warm owing to the sunlight they received in the previous hours, and, as a result, subsurface water ice keeps sublimating and finding its way to the surface through the comet’s porous interior.

But as soon as this “underground” water vapor reaches the cold surface, it freezes again, blanketing that patch of comet surface with a thin layer of fresh ice.

Eventually, as the Sun rises again over this part of the surface on the next comet day, the molecules in the newly formed ice layer are the first to sublimate and flow away from the comet, restarting the cycle.

“We suspected such a water ice cycle might be at play at comets, on the basis of theoretical models and previous observations of other comets but now, thanks to Rosetta’s extensive monitoring at 67P/Churyumov-Gerasimenko, we finally have observational proof,” said Fabrizio Capaccioni, VIRTIS principal investigator at INAF-IAPS in Rome, Italy.

From these data, it is possible to estimate the relative abundance of water ice with respect to other material. Down to a few cm deep over the region of the portion of the comet nucleus that was surveyed, water ice accounts for 10-15% of the material and appears to be well-mixed with the other constituents.

The scientists also calculated how much water vapor was being emitted by the patch that they analyzed with VIRTIS, and showed that this accounted for about 3% of the total amount of water vapor coming out from the whole comet at the same time, as measured by Rosetta’s MIRO microwave sensor.

“It is possible that many patches across the surface were undergoing the same diurnal cycle, thus providing additional contributions to the overall outgassing of the comet,” adds Dr. Capaccioni.

The scientists are now busy analyzing VIRTIS data collected in the following months, as the comet’s activity increased around the closest approach to the Sun.

“These initial results give us a glimpse of what is happening underneath the surface, in the comet’s interior,” according to Matt Taylor, ESA Rosetta Project Scientist.

Learn more about the Rosetta comet exploration at the mission’s web site.

Halfway through a Year in Space

NASA Marks an Important Milestone:

Join in the Conversation

Astronauts Scott Kelly and Mikhail Kornienko in a pre-launch image. Courtesy NASA

Just six months ago, astronaut Scott Kelly and cosmonaut Mikhail Kornienko blasted off for a year-long sojourn on the International Space Station. Tuesday, September 15 marks their halfway point and NASA is celebrating with a National Press Club event that will include a live interview with men, streamed on NASA.TV.

Find out what it’s like to live in space for long periods of time, and what these men hope to teach the rest of us about humanity’s future in space.
The televised portion of the event will air on NASA Television and the agency’s website from 9 to 10 a.m. at:

The Pipeline from Pluto Resumes

The High-Res Images Flow

In the center of this 300-mile (470-kilometer) wide image of Pluto from NASA’s New Horizons spacecraft is a large region of jumbled, broken terrain on the northwestern edge of the vast, icy plain informally called Sputnik Planum, to the right. The smallest visible features are 0.5 miles (0.8 kilometers) in size. This image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Courtesy New Horizons/JHU/NASA/SWRI
In the center of this 300-mile (470-kilometer) wide image of Pluto from NASA’s New Horizons spacecraft is a large region of jumbled, broken terrain on the northwestern edge of the vast, icy plain informally called Sputnik Planum, to the right. The smallest visible features are 0.5 miles (0.8 kilometers) in size. This image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Courtesy New Horizons/JHU/NASA/SWRI

The image pipeline from Pluto via New Horizons is up and running again, the first images are incredibly detailed and beautiful. They reveal a bewildering variety of surface features that have scientists reeling because of their range and complexity. According to Principal Investigator Alan Stern, the diversity of the landforms and the processes they belie are almost unbelievable. “If an artist had painted this Pluto before our flyby, I probably would have called it over the top — but that’s what is actually there,” he said.

The spacecraft began its year-long download of new images and other data over the Labor Day weekend. They reveal new features as diverse as possible dunes, nitrogen ice flows that apparently oozed out of mountainous regions onto plains, and even networks of valleys that may have been carved by material flowing over Pluto’s surface. They also show large regions that display chaotically jumbled mountains reminiscent of disrupted terrains on Jupiter’s icy moon Europa.

“The surface of Pluto is every bit as complex as that of Mars,” said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging (GGI) team at NASA’s Ames Research Center in Moffett Field, California. “The randomly jumbled mountains might be huge blocks of hard water ice floating within a vast, denser, softer deposit of frozen nitrogen within the region informally named Sputnik Planum.”

New images also show the most heavily cratered — and thus oldest — terrain yet seen by New Horizons on Pluto next to the youngest, most crater-free icy plains. There might even be a field of dark wind-blown dunes, among other possibilities.

“Seeing dunes on Pluto — if that is what they are — would be completely wild, because Pluto’s atmosphere today is so thin,” said William B. McKinnon, a GGI deputy lead from Washington University, St. Louis. “Either Pluto had a thicker atmosphere in the past, or some process we haven’t figured out is at work. It’s a head-scratcher.”

For more information and additional images, visit the Pluto pages at: and the mission Web site at:

Make Plans for White House Astronomy Night

President Obama looks through a telescope at the White House during the 2009 White House Astronomy Event. Courtesy Chuck Kennedy.

Mark your calendar for the next Astronomy Night hosted by the United States White House and the President on October 19, 2015.

The event will bring together scientists, engineers, and visionaries from astronomy and the space industry to share their experiences with students and teachers as they spend an evening stargazing from the South Lawn. In addition to inspiring students and stargazers from across the country to learn about the newest astronomical discoveries and the technologies that enable us to explore and live in space, we are continuing progress on the President’s call to action to expand access and opportunities for students and adults to participate in the wonders of science and space.

Organizers also hope that scientists and amateur astronomers will host events in their local observatories, planetarium facilities, museums, and astronomy clubs the same night. Planners are welcome to share their events with everyone by filling out a Share the Event form.

For more information about White House Astronomy Night, visit the Event Web page.

The last White House Astronomy night was in 2009 and featured a portable dome set up on the White House lawn, as well as telescopes provided by local-area amateur observers.

Hang Out with Pluto Experts

Want to Find out the Latest about Pluto?

Pluto and Charon just before close flyby of the New Horizons spacecraft. Courtesy NASA/JHUAPL/SWRI.
Pluto and Charon just before close flyby of the New Horizons spacecraft. Courtesy NASA/JHUAPL/SWRI.

There’s a Google Hangout happening on Wednesday, August 26th that will bring you the latest news from Pluto, shared by experts in the field. It’s being hosted by the Kavli Foundation, and will focus on information from New Horizons team members Richard Binzel and Cathy Olkin, as well as insights from planetary scientist Michael Brown of CalTech, and writer Adam Hadhazy.

As the data from the mission streams back to Earth, team members are analyzing and interpreting what the most distant planet has to tell them. In particular, they are intrigued by Pluto’s atmospheric loss, its unusual terrains, and the very different face of Charon that also shows fascinating features. This hangout features what they know so far and what they think is happening in the Pluto system.

Tune in next week at for Pluto Revealed: New Horizons’ Historic Voyage. It begins at 15:30 EDT (19:30 UTC) and runs for 30 minutes.

Send Your Name to Mars

Artist’s concept of Mars InSight as it is deployed on Mars. Courtesy NASA/JPL-Caltech

There’s a data chip on a spacecraft that’s just waiting for you to add your name to it. The  mission is NASA/JPL’s InSight project, which will  launch in 2016. Mission planners are inviting the public to send their name to Mars via the spacecraft.

If you’re interested, check out the Send Your Name to Mars Web site; if you’ve sent your name to space through this site before, you’ll log in as a frequent flyer. If not, just create a new “passenger” name, and you’re on your way.

The fly-your-name opportunity comes with “frequent flier” points to reflect an individual’s personal participation in NASA’s journey to Mars, which will span multiple missions and multiple decades. The InSight mission offers the second such opportunity for space exploration fans to collect points by flying their names aboard a NASA mission, with more opportunities to follow.

You’re a frequent flyer if you sent your name aboard the first flight of NASA’s Orion spacecraft last December. This is the craft that will ultimately carry astronauts to deep space destinations including Mars and an asteroid. After InSight, the next opportunity to earn frequent flier points will be NASA’s Exploration Mission-1, the first planned test flight bringing together the Space Launch System rocket and Orion capsule in preparation for human missions to Mars and beyond.

InSight will launch from Vandenberg Air Force Base, California in March 2016 and land on Mars Sept. 28, 2016. This mission is dedicated to studying the deep interior of Mars, to learn more about Mars quakes and seismic waves that help planetary scientists map the inside of a planet.  It also will deploy a self-hammering heat probe that will burrow deeper into the ground than any previous device on the Red Planet. These and other InSight investigations will improve our understanding about the formation and evolution of all rocky planets, including Earth.  To get more information about InSight, check out the mission Web page.


Light Pollution as Seen from Space

Astronaut Images from ISS Illuminate a Problem

The glow from cities extends far beyond the city limits, and includes light pollution as a result of scattered light.

The International Space Station is an invaluable resource for science research in space, but it is also a fantastic way for us to see how our planet looks from space. Thousands of images taking by astronauts are showing us how the night side of our planet is being affected by light pollution.

Researchers are using astronaut images of light-polluted regions taken by astronauts aboard the International Space Station (ISS) to measure the amount of light pollution worldwide.  It includes cities and towns, but also measures scattered light. Until now, such faint glows had not been measured quantitatively. This diffuse glow, which is seen from space, is scattered from streetlights and buildings, and is responsible for the brightening of the night skies in and around cities. Such glows drastically limit the visibility of faint stars and the Milky Way.

Recent studies indicate that European countries and cities with a higher public debt also have higher energy consumption for street lighting per inhabitant, and that the total cost of the energy consumption for street lights is 6,300 million euros/year in the European Union. The findings were presentedat the IAU XXIX General Assembly in Honolulu, Hawaii.

In a remarkable new study, scientists from the Universidad Complutense de Madrid, Spain and the Cégep de Sherbrooke in Canada, together with members of the public, have worked on a project called Cities at Night. The aim is to produce a global color map of the Earth [1] at night from pictures taken by astronauts on the International Space Station using a standard digital camera.

Starting in July 2014, this huge project required the cataloging of over 130,000 images — the ISS’s entire high-resolution archive — and geo-referencing them to place them on a map. The images were also calibrated using the stars in the background sky over the ISS, as well as ground-based measurements of the night sky brightness.

Previously, light pollution measurements had to be done in situ and would contribute only a single measurement to the light pollution map. This new method, connecting space-based measurements of light pollution with ground-based night sky brightness measurements, makes it possible, for the first time, to map light pollution reliably over extended areas.

A diffuse light present around cities, in addition to the familiar bright lights from streets and factories, was previously detected by the Defense Meteorological Satellite Program, but its nature remained unknown; the satellite’s low-resolution cameras could not distinguish it from other instrumental factors. However, the high-resolution images captured by the astronauts, in addition to an extensive sky brightness survey conducted around Madrid, have now allowed scientists to observe the direct relationship between the diffuse light observed and light pollution from artificial lights.

Using the ISS astronaut images, as well as data from the Defense Meteorological Satellite Program and the Suomi National Polar-orbiting Partnership Satellite, the researchers also discovered that European countries and cities that have a higher public debt also have a higher energy consumption of street lighting per inhabitant. The total cost of the energy consumption for streetlights is estimated by the study to be 6300 million euros/year in the European Union. The different ways of calculating streetlight energy costs across Europe previously made such an estimate impossible.

This citizen science project is vital for researchers from many scientific fields. Studying lighting technology from orbit is currently of even greater importance now than before due to massive transitions to LED technology. The ISS is the only place from which it is possible to estimate the prevalence of the different types of lighting technologies used in cities around the world and to measure the impact of light pollution on the environment and human health.

The Perseids are Coming!

Summer’s Great Meteor Shower


A Perseid meteor flares along the path of the Milky Way in this image by Brocken Inaglory, CCA-SA.
A Perseid meteor flares along the path of the Milky Way in this image by Brocken Inaglory, CCA-SA.

Skygazers are gearing up for the annual return of the Perseid meteor shower. It’s already happening, but the best times to view the most number of meteors are from late in the evening August 12th into the early morning hours of August 13th. This is when Earth will be in the thick of a stream of debris flung off by the comet Swift-Tuttle as it rounds the Sun in its orbit. The wee hours of the morning mark the time when Earth “rotates” into the oncoming trail that creates the meteor shower.

The stream of material from Comet Encke, which forms the basis of the Taurids meteors showers. Courtesy NASA/Spitzer Space Telescope

These are tiny chunks of debris, most the size of a speck of dust or a grain of sand. But, when they encounter Earth’s atmosphere, they heat up due to friction with the gas molecules. That heats up the debris, and eventually it gets so hot it vaporizes. That’s what we see as a meteor flaring across the sky. If, for some reason, a chunk of debris makes it to Earth’s surface, that piece of space rock is known as a meteorite.

How to Observe the Perseids

perseidmap_stripWatching for meteor showers is one of the easiest observing projects you can do. You simply go outside and look up, preferably toward the constellation Perseus. It happens that the stream we are passing through is roughly aligned with the constellation, so that’s why we see the meteors appear to radiate from that region of the sky. You’ll see meteors all over the sky, and if conditions are good, you could see up to dozens per hour. This year, the viewing is good because the Moon won’t be washing out the sky. The best time to see the most meteors will be after midnight, although you’re likely to see a few in the hour or two before.

The best thing to do is set up a lawn chair outdoors in a safe spot away from bright lights. Make sure you’re dressed warmly, even if though it’s summertime for most observers. Late evenings and early morning hours can get chilly.

See how many meteors you can count in an hour. Note their colors as they flare across the sky. And, if you’re an amateur radio fan, you can “listen” to meteor showers, too. Check out this page at for more information.

Happy Perseid-gazing!