Cassini's legacy after two decades at Saturn

Scientists on Earth have received the last submission from the Cassini spacecraft. It descended into Saturn’s atmosphere at 122,500 kilometers per hour, which caused it to melt, thereby ensuring that Saturn’s moons Titan and Enceladus would remain protected from possible contamination by any errant Earth microbes. Cassini scientists had considered other options for the spacecraft’s end, including leaving it to float endlessly in space or parking it in orbit around Saturn. But ultimately, they chose to have it descend into Saturn’s atmosphere after deciding the data that could be returned from the descent were more valuable than any further data it might obtain by remaining in space. Scientists will make discoveries from these data for decades to come.

15 Sep 2017

Mars class of 2020: A diverse group of missions takes aim at the red planet

As many as six missions to Mars might launch in summer 2020, representing a growing and increasingly diverse interest in interplanetary space exploration.
15 Sep 2017

A great time to land on Mars

The 2020 window represents an especially good opportunity for missions looking to reach the Martian surface because of favorable environmental conditions on the planet early in 2021 when the spacecraft will arrive. The elliptical shape of Mars’ orbit means that the planet is, at times, much closer to or farther from the sun, so the amount of sunlight hitting the planet varies dramatically through the Martian year. Meanwhile, the tilt of Mars’ axis, as on Earth, leads to a progression of seasons as the orientations of the northern and southern hemispheres with respect to the sun change regularly and oppositely. The combination of Mars’ orbit and tilt drives an annual cycle of swings in atmospheric pressure of up to about 25 percent as carbon dioxide freezes out of, or sublimes into, the atmosphere.

15 Sep 2017

Making oxygen with MOXIE

The MOXIE (Mars OXygen In-situ resource utilization Experiment) instrument on NASA’s 2020 rover is designed to demonstrate technology that can generate oxygen from carbon dioxide in the Martian atmosphere. Scaled-up versions of the technology could one day be used to produce the large amounts of fuel needed to boost rockets back off the planet’s surface, as well as to create breathing oxygen for human settlements.

15 Sep 2017

Geomedia: Books: Exploring space is risky business

Space is deadly, and the explorers who risk their lives to venture farther into these depths rank among the bravest heroes of all time. In “Mankind Beyond Earth: The History, Science, and Future of Human Space Exploration,” Claude A. Piantadosi portrays the history and future of space exploration through the lens of space medicine, which reminds us of the many threats to the human body that await as we venture away from our planet.

30 Aug 2017

Why meteors snap, crackle and pop

Keen-eared observers sometimes report hearing popping, whistling or buzzing at the same time they see meteors pass far overhead, a perplexing phenomenon called the electrophonic effect. What causes the effect — or if it’s even real — has been discussed for centuries; famed astronomer Edmond Halley is said to have dismissed it as a figment of people’s imaginations. In a new study in Geophysical Research Letters, researchers suggest that not only is it real, but that it is caused by radio waves induced by meteors and converted to sound waves near Earth’s surface.

17 Aug 2017

Comment: In space, timing is everything

From concept to launch, planetary missions are the result of years of planning and work, but success can hinge on a few events that happen in mere seconds.
10 Aug 2017

Red Planet Roundup: August 2017

With two rovers patrolling the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

03 Aug 2017

Titan's oddly oriented dunes may be electrostatically sculpted

Saturn’s largest moon, Titan, which has a dense, nitrogen-rich atmosphere with evidence of large amounts of frozen water at the surface, is a world apart from Earth’s moon. Among other strange phenomena, Titan has vast fields of frozen hydrocarbon particles that form 100-meter-tall dunes whose crests point east, opposite the prevailing west-blowing winds predicted by atmospheric models of Titan. In a new study in Nature Geoscience, researchers have found that these mysterious dunes may be sculpted in part by electrostatic charging of the frozen hydrocarbon grains.

01 Aug 2017

Earth-like exoplanet shows signs of supporting life

A recently discovered exoplanet 40 light-years from Earth appears to orbit its home star at a distance suggesting it could support liquid water. The planet, dubbed LHS 1140b and reported in a study in Nature, is located in the constellation Cetus and orbits a red dwarf star. The rocky planet is 10 times closer to its star than Earth is to the sun, but the red dwarf only puts out a fraction of the light that the sun does, meaning LHS 1140b lies in the middle of the habitable zone around the star.

24 Jul 2017