The origin of ice and organic matter on Mercury

Scientists discovered ice on Mercury. Ice and organic materials can be brought to this planet by comets. Mercury is the smallest planet and the closest planet in our solar system.

>>>Mercury is not a dead planet

The planet has orbits around the sun lasting only 88 days, creating a tight orbit keeping it surprisingly warm. Mercury surface temperature can reach 800 degrees Fahrenheit - hot enough to liquefy lead.

Currently, NASA researchers, MIT (Massachusetts Institute of Technology), University of California at Los Angeles (UCLA) and several other agencies have discovered evidence that Mercury may contain vesicles. with organic substances, in some eternal craters located near the north pole of Mercury.

This surprising finding suggests scientists that both ice and organic matter, such as carbon, can be deposited on Mercury's surface due to comets or asteroids. Over time, this volatile material may then have moved to the polar region of the planet.

"We think the most interesting finding could be that it is really ice," said Maria Zuber, EA Griswold Professor of Geophysics at MIT's Department of Earth, Atmospheric and Earth Sciences, and is The team member said. "However, the identification of dark, insulating materials can show that complex organic substances make the story even more thrilling."

Zuber and her colleagues published their findings this week in the journal Science.

The ability of ice to exist on Mercury is not new: In the 1990s, radar observations detected Mercury's near-bright light that scientists believe could be a sign of ice or a planetary rough surface. However, the evidence is not convincing for either scenario.

To get a clearer picture of Mercury's polar regions, Zuber and her colleagues analyzed NASA's Messenger mission (MErcury Surface, Space ENvironment, GEochemistry and Ranging). Messenger is a probe that has circled around and mapped the planet for April 2011.

Surface mapping of the planet is a challenging task, when the probe must overcome the intense radiation of the sun, these radiation may be "devastating to electronic devices". What's more, the probe moves from the polar to the polar region in an elliptical orbit, making an extremely difficult mapping task, despite the challenges, Messenger has Accumulating more than 10 laser pulses, these laser pulses have been used for topographic mapping and measuring the near infrared reflectivity of the surface.

Last year, researchers analyzed the topographic observations of the probe and created a high-resolution map of Mercury. The researchers then covered this map to observe the radar earlier. They found that the bright areas were discovered in the radar lining up with the shadow of the permanent crater at the planet's north pole - the area that never had the sun, and that was the ideal place. for tape exist. This finding is a proof that Mercury may have ice.

In the latest analysis of Messenger's observational results, scientists believe they have found compelling evidence that there is water freezing on Mercury, although the data is initially difficult to understand.

The team found that probe measurements of the probe were performed via a high-altitude laser, consistent with the previous radar high-altitude northern region of Mercury. Two exceptionally bright craters, in both radar and at laser wavelengths, show the presence of reflective tape. However, just south of the craters, other places are quite dark with high altitude lasers, but bright in radar.

Observations "have pushed us for a long time , " Zuber said, until a member of the group, UCLA's David Paige, developed a thermal model of the planet. Using observation of Mercury Messenger, terrain and rotation characteristics, simulating the sun's illumination model of the planet, allowing to accurately determine the surface temperature and below the surface of Mercury.

The results show that the bright spots correspond to areas where ice has stabilized on the surface, in dark areas, ice is already stable within one meter of the surface. Dark insulating materials are suitable for complex organic substances that are already dark but may be further darkened by high radiation on Mercury's surface.

In addition, the neutron Messenger spectrometer detected hydrogen in the vicinity of Mercury's north pole. The combination of component observations, spectra and geometry and thermal models provide a suitable explanation for unusual scattering radar observations.

Paul Lucey, a professor of geophysics and planetarium at the University of Hawaii, points out that Messenger also showed some areas where surfaces are much darker in previous radar measurements. Lucey interpreted these results as inferred evidence of ice on Mercury's surface.

"This shows that in the past, ice was spread over Mercury, and narrowed to its current state , " said Lucey, who did not participate in the study. "Even Mercury experienced global warming."

Messenger will continue to spin around Mercury, and Zuber says future data may reveal more information about the planet.