Science Daily: Comets and Asteroids

Star birth with a chance of Winds?

The lesser-known constellation of Canes Venatici (The Hunting Dogs), is home to a variety of deep-sky objects -- including this beautiful galaxy, known as NGC 4861. Astronomers are still debating on how to classify it. While its physical properties -- such as mass, size and rotational velocity -- indicate it to be a spiral galaxy, its appearance looks more like a comet with its dense, luminous 'head' and dimmer 'tail' trailing off. Features more fitting with a dwarf irregular galaxy.

Urban collection of modern-day micrometeorites

More than 100 billion micrometeorites (MMs) fall to Earth each year. Until now, scientists have believed that these particles could only be found in the cleanest environments, such as the Antarctic. Now they show that, contrary to that expectation, micrometeorites can be recovered from city rooftops and that, unlike those from the Antarctic, they are the youngest collected to date.

Micro spacecraft investigates cometary water mystery

In September 2015, a team of astronomers successfully observed the entire hydrogen coma of the comet 67P/Churyumov-Gerasimenko, using the LAICA telescope onboard the PROCYON spacecraft. They also succeeded in obtaining the absolute rate of water discharge from the comet. Through our observations, we were able to test the coma models for the comet for the first time. This result is the first scientific achievement by a micro spacecraft for deep space exploration.

Rare meteorites challenge our understanding of the solar system

Researchers have discovered minerals from 43 meteorites that landed on Earth 470 million years ago. More than half of the mineral grains are from meteorites completely unknown or very rare in today's meteorite flow. These findings mean that we will probably need to revise our current understanding of the history and development of the solar system.

Today's rare meteorites were once common

Four hundred and sixty-six million years ago, there was a giant asteroid collision in outer space, and the debris from that collision has been falling to Earth ever since. But for the first time, scientists have created a reconstruction of the kinds of meteorites that fell before this collision. They discovered that today's common meteorites were once rare, while many meteorites that are rare today were common before the collision.

Quantum optical sensor tested in space for the first time, with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequisite for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

Deep-space mission to metal asteroid

Scientists are planning to send a deep-space probe to a metal asteroid, enabling them to see what is believed to be a planetary core. Psyche, an asteroid orbiting the sun between Mars and Jupiter, is made almost entirely of nickel-iron metal.

A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers

Like cosmic lighthouses sweeping the universe with bursts of energy, pulsars have fascinated and baffled astronomers since they were first discovered 50 years ago. In two studies, international teams of astronomers suggest that recent images from NASA's Chandra X-ray Observatory of two pulsars -- Geminga and B0355+54 -- may help shine a light on the distinctive emission signatures of pulsars, as well as their often perplexing geometry.

The moon is older than scientists thought

The moon is much older than some scientists believe, a research team now reports. Their precise analysis of zircons bought to Earth by Apollo 14 astronauts reveals the moon is at least 4.51 billion years old and probably formed only about 60 million years after the birth of the solar system -- 40 to 140 million years earlier than recently thought.

Our galaxy's black hole is spewing out planet-size 'spitballs'

Every few thousand years, an unlucky star wanders too close to the black hole at the center of the Milky Way. The black hole's powerful gravity rips the star apart, sending a long streamer of gas whipping outward. That would seem to be the end of the story, but it's not. New research shows that not only can the gas gather itself into planet-size objects, but those objects then are flung throughout the galaxy in a game of cosmic 'spitball.'

Looking for life in all the right places, with the right tool

Researchers have invented a range of instruments from giant telescopes to rovers to search for life in outer space, but so far, these efforts have yielded no definitive evidence that it exists beyond Earth. Now scientists have developed a new tool that can look for signs of life with 10,000 times more sensitivity than instruments carried on previous spaceflight missions.

How a moon slows the decay of Pluto's atmosphere

A new study provides additional insight into relationship between Pluto and its moon, Charon, and how it affects the continuous stripping of Pluto's atmosphere by solar wind. When Charon is positioned between the sun and Pluto, the research indicates that the moon can significantly reduce atmospheric loss.

How Earth's previous moons collided to form the moon: New theory

A new theory suggests the Moon we see every night is not Earth's first moon, but rather the last in a series of moons that orbited our planet. Moons formed through the process could cross orbits, collide and merge, slowly building the bigger moon we see today.

Hubble detects 'exocomets' taking the plunge into a young star

Interstellar forecast for a nearby star: Raining comets! NASA's Hubble Space Telescope has discovered comets plunging onto the star HD 172555, which is a youthful 23 million years old and resides 95 light-years from Earth.

Astronomers discover cosmic double whammy

Astronomers have discovered a cosmic one-two punch never seen before. By combining data from some of the best X-ray, optical and radio telescopes in the world, researchers have found out what happens when matter ejected by a giant black hole is swept up in the merger of two enormous galaxy clusters.

Deepest X-ray image ever reveals black hole treasure trove

An unparalleled image from NASA's Chandra X-ray Observatory is giving astronomers the best look yet at the growth of black holes over billions of years beginning soon after the Big Bang. This is the deepest X-ray image ever obtained, collected with about 7 million seconds, or 11 and a half weeks, of Chandra observing time.