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Tag Archives: atmosphere

From a European Space Agency (ESA) press release, May 16. 2014:

After eight years in orbit, ESA’s Venus Express orbiting mission has completed routine science observations and is preparing for a daring plunge into the planet’s hostile atmosphere. Its suite of seven instruments have provided a comprehensive study of the ionosphere, atmosphere and surface of Venus.

Credit: ESA, C. Carreau

Credit: ESA, C. Carreau

The spacecraft’s fuel supplies, necessary to maintain its elliptical orbit, are running low and will soon be exhausted. The routine science operations concluded this week and the spacecraft is being prepared for one final mission: to make a controlled plunge deeper into the atmosphere than ever before attempted.

This experimental ‘aerobraking’ phase is planned for June 18 – July 11, during which time some limited science measurements with the spacecraft’s magnetic field, solar wind and atom analyzing instruments will be possible. Also, temperature and pressure sensors will record the conditions that the spacecraft experiences.

It is possible that the remaining fuel in Venus Express will be exhausted during this phase or that the spacecraft does not survive these risky operations. But if the spacecraft is still healthy afterwards, its orbit will be raised again and limited operations will continue for several more months, fuel permitting. However, by the end of the year, it is likely that Venus Express will have made its final descent into the atmosphere of the planet, bringing a fantastic scientific endeavor to an end.

Links: ESA press release; link to aerobraking movie (approx 1 min 30 s).




Have you ever wondered what would it be like to see a sunset on Mars? To help find out, the robotic rover Spirit was deployed in 2005 to park and watch the Sun dip below the distant lip of Gusev crater.

Credit: Mars Exploration Rover Mission, Texas A&M, Cornell, JPL, NASA

Colors in the above image have been slightly exaggerated but would likely be apparent to a human explorer’s eye. Fine martian dust particles suspended in the thin atmosphere lend the sky a reddish color, but the dust also scatters blue light in the forward direction, creating a bluish sky glow near the setting Sun. Because Mars is farther away, the Sun is less bright and only about two thirds the diameter it appears to us from Earth. Images like this help atmospheric scientists understand not only the atmosphere of Mars, but atmospheres across the Solar System, including on our home planet, Earth.

Link: APOD March 2, 2014