Sentences with phrase «surfaces by comets»

«The detection of these compounds in comets helps to expand our knowledge of... the potential ingredients for life that could have been delivered to the early Earth or other planetary surfaces by comets,» says Jamie Elsila, an astrochemist at NASA.

Not exact matches

The meteorite is made of volcanic rock, and the presence of water in it suggests that crustal rocks on Mars interacted with surface water that was delivered by volcanic activity, near - surface reservoirs or by impacting comets, Agee says.

The finding suggests the comet's surrounding cloud of gas and dust may largely be fed by underlying ices, rather than by gas streaming off its surface.

Instead, it may be generated by interactions of water, the solar wind and sand on the comet's surface.

Brown University researchers have produced new evidence that lunar swirls — wispy bright regions scattered on the Moon's surface — were created by several comet collisions over the last 100 million years.

A'Hearn says he hopes eventually to understand the comet's geologic structure and even estimate its gravity by watching how the debris falls back to its surface.

The other finalist, the Comet Astrobiology Exploration Sample Return (CAESAR) mission, would launch a spacecraft before the end of 2025 to collect a 100 - gram sample from the surface of comet 67P, which was mapped by ESA's Rosetta spacecraft, and return it to Earth in 2038.

Researchers speculate that the comet's boulders might have been relocated by surface material slipping and sliding after being heated by the sun.

Three boulders (shown) balance precariously on comet 67P / Churyumov - Gerasimenko in this Sept. 16 image taken 29 kilometers above the surface by the Rosetta spacecraft

The enticing evidence was delivered by the Rosetta spacecraft's OSIRIS instrument, which snaps photos of the comet's surface with a resolution as high as a few centimeters per pixel.

These particles probably collected on the comet's surface after its previous close swing by the sun six - and - a-half years ago.

However, gravity on the comet is also very weak, and an analysis of the forces exerted on the grains at the comet's surface shows that these thermal winds can transport centimeter - scale grains, whose presence has been confirmed by images of the ground.

On average, material blasted across Mercury's surface by relatively recent impacts of comets, asteroids, and other small bodies reflects only two - thirds as much light as freshly excavated material on the moon, previous studies have shown.

They also looked at whether craters made by the comets hitting the surface could excavate enough nitrogen — but that would require a very deep layer of nitrogen ice at the surface, which is not proven.

Recent modeling along with previously published results from NASA's MESSENGER spacecraft — short for Mercury Surface, Space Environment, Geochemistry and Ranging, a mission that observed Mercury from 2011 to 2015 — has shed new light on how certain types of comets influence the lopsided bombardment of Mercury's surface by tiny dust particles called micrometeSurface, Space Environment, Geochemistry and Ranging, a mission that observed Mercury from 2011 to 2015 — has shed new light on how certain types of comets influence the lopsided bombardment of Mercury's surface by tiny dust particles called micrometesurface by tiny dust particles called micrometeoroids.

COVER View of a cliff and gravel field on the small lobe of comet 67P / Churyumov - Gerasimenko from a distance of 8 kilometers to the surface, as seen by Rosetta / OSIRIS.

They reasoned that without continual renewal, the surfaces of such bodies should have become densely covered with craters as a result of impacts by meteorites and comets over the 4.5 billion years that they have existed.

A comet usually too faint to be seen with the naked eye has brightened by a factor of a million since Tuesday, suggesting its surface may have cracked open and expelled clouds of dust and gas.

This could be good news for life under the surface, as tectonics would deliver new material — including organic molecules deposited by comets — to this environment, which is otherwise completely sealed off from space.

The consortium instruments are designed to study a number of phenomena, including the interaction of 67P / C - G with the solar wind, a continuous stream of plasma emitted by the sun; changes of activity on the comet; the structure and dynamics of the comet's tenuous plasma atmosphere, known as the coma; and the physical properties of the comet's nucleus and surface.

Unexpected surprise: a final image from Rosetta 28 September 2017 Scientists analysing the final telemetry sent by Rosetta immediately before it shut down on the surface of the comet last year have reconstructed one last image of its touchdown site.

In addition to water, organic molecules, which could have been deposited on the surface by crashing comets, somehow would have to get through the thick shells of ice for life to form, a situation that puts Saturn's geyser - spewing moon Enceladus at the top of Nimmo's list of potential spots for life.

The comets and asteroids sampled by past and ongoing missions have already polluted Earth's surface, and NASA has deemed these objects unlikely to harbor life.

The comet appears to have undergone visible changes, including the changes in the size and number of surface features such as smooth patches, pits, and craters, and the loss of ice vaporized by the Sun or blasted off its surface by the Solar Wind into its tail as well as failing back on the object like snow, so that it appears to shrink, on average, by 25 to 50 centimeters (9.2 to 19.7 inches) with each orbit around the Sun.

Ideas that commonly surface include perturbations to the earth's orbit by other planets, disruptions of ocean currents, the rise and fall of greenhouse gases, heat reflection by snow, continental drift, comet impacts, Genesis floods, volcanoes, and slow changes in the irradiance of the sun.