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Astronomy

This view, from 478,000 miles, shows that Pluto is home to huge, 11,000-foot tall mountains, most likely composed of ice and frozen methane and nitrogen. The lack of impact craters suggests that Pluto’s surface is young, probably less than 100 million years old. Courtesy of NASA/APL/SwRI

When Alan Calder was young, his father used to share the world of the planets and stars with him through telescopes in their backyard. Peter Tarr, meanwhile, drew pictures in his teenage notebooks of Saturn and Jupiter and saved enough money to travel to Africa aboard a ship with Neil Armstrong to view a solar eclipse.

This past week, Calder, Tarr, and many others who have craned their necks skyward received the first set of clear images from Pluto, a dwarf planet located more than three billion miles from Earth.

The New Horizons space probe, which the National Aeronautics and Space Administration blasted off from Earth in 2006, beamed back the first pictures of a dwarf planet that had, up until recently, been considered something of a gray, icy blob.

Traveling at the speed of light, the images took four and a half hours to reach the eager eyes of astronomers and scientists around the world. Long Islanders shared the excitement surrounding these first close-up views of a planet named, by then 11-year old Venetia Burney, more than eight decades ago.

“Our imaginations tend to fail us” when anticipating what’s around the corner or, more precisely, billions of miles away, said Frederick Walter, a professor of astronomy who specializes in stars and teaches a solar system course at Stony Brook. Pluto “doesn’t look like any of the worlds we know.”

Astronomers have zeroed in on the 11,000 foot high ice mountains, which, NASA scientists said, are likely made of a combination of ice and frozen methane and nitrogen.

The show stopper in these early images, however, was the lack of something many of them were sure would be there: impact craters. These craters are like the ones that riddle the surface of Earth’s moon and that have also affected the geology of our planet.

New Horizons captured this stunning image, on July 13, of one of Pluto’s most dominant features, the “heart.” It’s estimated to be 1,000 miles across at its widest point and rests just above the equator. The heart’s diameter is about the same distance as from Denver to Chicago. Courtesy of NASA/APL/SwRI
New Horizons captured this stunning image, on July 13, of one of Pluto’s most dominant features, the “heart.” It’s estimated to be 1,000 miles across at its widest point and rests just above the equator. The heart’s diameter is about the same distance as from Denver to Chicago. Courtesy of NASA/APL/SwRI

“Some process has been resurfacing this planet, to smooth it out and get rid of whatever craters it should have,” said Deanne Rogers, an assistant professor in the Department of Geosciences at Stony Brook. “That was a real surprise for me.”

At this point, any explanation of the process that might melt and smooth out the surface of a planet that takes 248 years to orbit the sun is speculation, Rogers added.

One such possibility is the presence of radioactive elements, researchers said.

Calder, who is an associate professor in the Department of Physics and Astronomy at Stony Brook, said he, too, is “intrigued by what seems to be the smooth surface of the planet. That implies an active geology.”

Calder’s research is in the field of star explosions. He said the images and information from Pluto wouldn’t impact his work too directly, unless scientists were able to show an interesting ratio of unexpected isotopes.

Calder said he’s looking forward to watching the textbooks change and seeing an alteration in the curriculum of classes on the solar system in light of the new images from the New Horizons satellite that are returning at such a slow pace that it will take 16 months for NASA to collect them all.

The active geology of this distant dwarf planet suggests that “even a small cold body that far out has activity on it,” Calder said.

For Tarr, a senior science writer at Cold Spring Harbor Laboratory, his interest in the planets date back to his teens. Traveling aboard a boat toward Africa to observe a solar eclipse, Tarr rubbed elbows with author Isaac Asimov, astronaut Armstrong, thousands of others interested in astronomy and fellow teenager Neil deGrasse Tyson, who would become an astrophysicist, author and director of the Hayden Planetarium.

For Tarr, some of the heroes of the Pluto images are the scientists who figured out, more than a decade ago, how to plot a course from Earth that would take the New Horizons spacecraft within 7,800 miles of Pluto.

“The calculation that goes into the launch is an incredible achievement,” Tarr said.

For Walter, part of the excitement of seeing these images comes from interpreting and understanding the unexpected parts of the picture.

“If you anticipated everything, you’d be doing the wrong thing,” Walter said. “Now that they’ve got these images” some of the old ideas will get “tossed out, and they’ll bring in something new” to explain the lack of craters, he added.

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Martian water, in a lab. Maria-Paz Zorzano, of the Centro de Astrobiologia in Madrid, Spain, recreates the conditions in which perchlorate salts would melt water during the Martian summer night. Photo from Maria-Paz Zorzano

By Daniel Dunaief

It’s not exactly an oasis filled with unexplored life in the middle of a barren dessert. Rather, it is likely a small amount of liquid water that forms during the night and evaporates during the day. What makes this water so remarkable and enticing, however, is that, while it’s in our solar system, it is far, far away: about 225 million miles.

The rover Curiosity, which landed on Mars in the summer of 2012 after a 253-day journey from Earth, has gathered weather data from the Gale Crater on the Red Planet for the last year. That data has suggested the likely presence of liquid water.

“The cool part of this is the present-day nature of it,” said Tim Glotch, an associate professor at the Department of Geosciences at Stony Brook University, who studies the role of water in shaping the surface of Mars. “It’s there right now.”

The Rover Environmental Monitoring Station  on NASA’s Curiosity Mars rover includes temperature and humidity sensors mounted on the rover’s mast. Photo from Maria-Paz Zorzano
The Rover Environmental Monitoring Station on NASA’s Curiosity Mars rover includes temperature and humidity sensors mounted on the rover’s mast. Photo from Maria-Paz Zorzano

The liquid water is in the form of brine, which is a mix of water and salts. The perchlorate salts on or near the surface of Mars melt the ice that forms during the cold parts of the Martian night. It’s similar, Glotch said, to the way salts melt black ice during a frigid Long Island evening.

Curiosity, which is about the size of a small car, can’t detect this liquid water because its electronics don’t operate during temperatures that plunge at night to around 100 degrees below zero Fahrenheit.

The findings, which were reported last week in the journal Nature Geosciences, have competing implications. For starters, said lead author Javier Martin-Torres, who works at Lulea University of Technology in Sweden and is a part of the Spanish Research Council in Spain and a member of Curiosity’s science team, the water is in one of the least likely places on Mars.

“We see evidence of conditions for brine in the worst-case scenario on Mars,” Martin-Torres said in a Skype interview last week from Sweden. “We are in the hottest and driest place on the planet. Because we know that perchlorates are all over the planet — which we have seen from satellite images — we think there must be brine everywhere.”

Given the radiation, temperature fluctuations and other atmospheric challenges, however, the conditions for life, even microorganisms, to survive in these small droplets of water are “terrible,” Martin-Torres said.

Still, the fact that “we see a water cycle, in the present atmosphere, is very exciting,” Martin-Torres said. “This has implications in meteorology.”

Deanne Rogers, an assistant professor in the Department of Geosciences at Stony Brook, said the likelihood of water bound to perchlorate salts directly affects her own research.

“Something I work on is sulfate minerals on Mars,” she said. “They can take on water and get rid of them easily by exchanging water vapor with the atmosphere.” She may incorporate perchlorates into future grant proposals.

Briny water, Rogers said, may also explain the dark streaks that appear on Mars at mid and low latitudes. These streaks look like running water going down a slope.

“People try to explain what these are,” she said. “It can’t be pure liquid water. It might be perchlorates taking on water vapor and producing dark streaks.”

By landing on the planet and sending readings back to researchers, Curiosity and other land-based vehicles can offer firsthand evidence of environmental conditions.

“Direct measurements are way more precise than what we can do from orbit,” Rogers said.

In the first week after the paper came out, Martin-Torres said he spent about 85 percent of his work time talking to the media, scientists or people asking questions about his studies. He has also received more than 10 times the typical number of requests from prospective Ph.D. students who would like to work in his lab while scientists from around the world have reached out to form collaborations.

Rogers explained that students might react to this kind of discovery the same way she did to other data and images from Mars in the early stages of her career.

“When Pathfinder landed in 1997, I saw the beautiful, colorful panoramas in the newspaper,” she said. “That’s when I knew what I was going to do. I hope that kids feel the same way.”

Martin-Torres, who said he has already submitted additional research proposals based on this discovery, described the current era of Mars research as the “golden age of Mars exploration.”

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