Science Daily: Comets and Asteroids

Mars' moon Phobos examined in a different light

NASA's longest-lived mission to Mars has gained its first look at the Martian moon Phobos, pursuing a deeper understanding by examining it in infrared wavelengths.

Milky Way's 'most-mysterious star' continues to confound

In 2015, a star called KIC 8462852 caused quite a stir in and beyond the astronomy community due to a series of rapid, unexplained dimming events. The latest findings from astronomers take a longer look at the star, going back to 2006 -- before its strange behavior was detected by Kepler.

The super-Earth that came home for dinner

It might be lingering bashfully on the icy outer edges of our solar system, hiding in the dark, but subtly pulling strings behind the scenes: stretching out the orbits of distant bodies, perhaps even tilting the entire solar system to one side. It is a possible "Planet Nine" -- a world perhaps 10 times the mass of Earth and 20 times farther from the sun than Neptune.

Extreme magnetic storm: Red aurora over Kyoto in 1770

Researchers used historic accounts of a rare red aurora over Kyoto, Japan, in the 18th century to support calculations of the strength of the associated magnetic storm. The September 1770 storm could be 3-10% stronger than the September 1859 storm, the greatest storm in the past 200 years. The research provides insights that could assist preparation for an unlikely, but possible, future intense magnetic storm.

Meteorite tells us that Mars had a dense atmosphere 4 billion years ago

Exploration missions have suggested that Mars once had a warm climate, which sustained oceans on its surface. To keep Mars warm requires a dense atmosphere with a sufficient greenhouse effect, while the present-day Mars has a thin atmosphere whose surface pressure is only 0.006 bar, resulting in the cold climate it has today. It has been a big mystery as to when and how Mars lost its dense atmosphere.

ALMA and Rosetta detect Freon-40 in space

Observations made with the Atacama Large Millimeter/submillimeter Array (ALMA) and ESA's Rosetta mission, have revealed the presence of the organohalogen Freon-40 in gas around both an infant star and a comet. Organohalogens are formed by organic processes on Earth, but this is the first ever detection of them in interstellar space. This discovery suggests that organohalogens may not be as good markers of life as had been hoped, but that they may be significant components of the material from which planets form.

Farthest active inbound comet yet seen

NASA's Hubble Space Telescope has photographed the farthest active inbound comet ever seen, at a whopping distance of 1.5 billion miles from the Sun (beyond Saturn's orbit). Slightly warmed by the remote Sun, it has already begun to develop an 80,000-mile-wide fuzzy cloud of dust, called a coma, enveloping a tiny, solid nucleus of frozen gas and dust. These observations represent the earliest signs of activity ever seen from a comet entering the solar system's planetary zone for the first time.

The volatile processes that shaped Earth

Although it is widely understood that Earth was formed gradually, from much smaller bodies, many of the processes involved in shaping our growing planet are less clear. Astronomers have now untangled some of these processes, revealing that the mini-planets added to Earth had previously undergone melting and evaporation. They also address another scientific conundrum: Earth's depletion in many economically important chemical elements.

Total solar eclipse viewed from space

While people across the nation gazed at August's total solar eclipse from Earth, a bread loaf-sized NASA satellite had a front row seat for the astronomical event.

Near-Earth asteroid CubeSat goes full sail

NASA's Near-Earth Asteroid Scout, a small satellite the size of a shoebox, designed to study asteroids close to Earth, recently performed a full-scale solar sail deployment test. The test was performed in an indoor clean room to ensure the deployment mechanism's functionality after recent environmental testing.

Lava tubes: Hidden sites for future human habitats on the Moon and Mars

Lava tubes, underground caves created by volcanic activity, could provide protected habitats large enough to house streets on Mars or even towns on the Moon, according to new research. A further study shows how the next generation of lunar orbiters will be able to use radar to locate these structures under the Moon's surface. 

Solar eruption ‘photobombed’ Mars encounter with Comet Siding Spring

When Comet C/2013 A1 (Siding Spring) passed just 140,000 kilometers from Mars on 19th October 2014, depositing a large amount of debris in the Martian atmosphere, space agencies coordinated multiple spacecraft to witness the largest meteor shower in recorded history. It was a rare opportunity, as this kind of planetary event occurs only once every 100,000 years.

Unique type of object discovered in our solar system

Astronomers have observed the intriguing characteristics of an unusual type of object in the asteroid belt between Mars and Jupiter: two asteroids orbiting each other and exhibiting comet-like features, including a bright coma and a long tail. This is the first known binary asteroid also classified as a comet.

Space radiation is risky business for the human body

NASA's Human Research Program (HRP) is working to protect the whole human body from radiation in space. Space radiation is dangerous and one of the primary health risks for astronauts. Virtually any cell in the body is susceptible to radiation damage.