Skip navigation

Tag Archives: Venus

From a news article in Nature, April 12, 2016:

After an unplanned 5-year detour, Japan’s Venus probe, Akatsuki, has come back to life and provided new images of Venus. These include a detailed shot of streaked, acidic clouds and a mysterious moving ‘bow’ shape in the planet’s atmosphere.

venus-combined-sideview

Credit: ISAS/JAXA

Akatsuki, which means ‘dawn’ in Japanese, launched in 2010 and was supposed to enter into orbit around Venus later that year to study the planet’s thick atmosphere. The mission would include looking for signs of active volcanos and other geology. However, upon entry, a fault in a valve caused the probe’s main engine to blow, and the craft entered an orbit around the Sun. As Akatsuki passed near Venus in December, Japan Aerospace Exploration Agency (JAXA) engineers managed to salvage the mission by instructing the craft’s much smaller, secondary thrusters to push it into a looping elliptical orbit around the planet. Its suite of five cameras capture light ranging from infrared to ultraviolet.

A highly detailed shot show dense layers within Venus’s sulfuric acid clouds. The highest-quality infrared image of this view of Venus, it suggests that the processes that underlie cloud formation might be more complicated than previously thought.

Advertisements

From an article on Sky and Telescope by David Dickinson, originally posted on December 9, 2015.

The Japanese Aerospace Exploration Agency’s (JAXA) Venus Climate Orbitor Akatsuki is finally orbiting Venus – five years later than planned. After a catastrophic main engine failure in 2010 causing the spacecraft to fly past Venus instead of entering its orbit, scientists and engineers have salvaged the mission and put Akatsuki back on track.

20151207_Akatsuki-Orbit-Insertion-update_Page_08_Image_0002

Credit: JAXA

On December 6th 2015, five years to the day of the original blip, four tiny reaction-control thrusters burned for more than 20 minutes to insert the spacecraft into Venusian orbit. Engineers had tested these thrusters to ensure it was possible back in 2011, before putting the spacecraft into hibernation to prolong its life. The first opportunity to execute the manouver came at the beginning of this month, and it proved to be second time lucky for JAXA’s spacecraft.

The six instruments aboard the Akatsuki spacecraft will probe Venus’s atmosphere, measuring its rotation and convection.Researchers also hope to detect evidence for Venusian lightning using a high-speed imager aboard the spacecraft. Viewing across radio, infrared, visible and ultraviolet wavelengths, the payload will also record heat radiated from the Venusian surface and may spot active volcanoes if they exist. A series of radio occultation experiments will also allow researchers to probe the depths of the Venusian atmosphere as the spacecraft makes successive passes behind the planet as seen from Earth.

In addition to the science payload, JAXA also teamed up with the Planetary Society to carry more than 260,000 people’s names and messages printed on aluminium plates aboard the spacecraft.

Whilst the new orbit time is much longer than originally planned, with a closest approach of 400km as opposed to the intended 300km, the JAXA engineers have saved the mission from disaster. Akatsuki, meaning ‘dawn’ in Japanese, will begin to send back its findings in 2016, and as it’s the first time that JAXA have managed to put a spacecraft in orbit around another planet, their wait will hopefully be rewarded.

For more information on the terrestrial planets, see Chapter 6 of The Cosmos.

Link to the original article here.

From an NRAO press release, March 9, 2015:

From earthbound optical telescopes, the surface of Venus is shrouded beneath thick clouds made mostly of carbon dioxide. To penetrate this veil, probes like NASA’s Magellan spacecraft use radar to reveal remarkable features of this planet, like mountains, craters, and volcanoes.

Credit: B. Campbell, Smithsonian, et al., NRAO/AUI/NSF, Arecibo

Credit: B. Campbell, Smithsonian, et al., NRAO/AUI/NSF, Arecibo

Recently, by combining the highly sensitive receiving capabilities of the National Science Foundation’s (NSF) Green Bank Telescope (GBT) and the powerful radar transmitter at the NSF’s Arecibo Observatory, astronomers were able to make remarkably detailed images of the surface of this planet without ever leaving Earth. The radar signals from Arecibo passed through both our planet’s atmosphere and the atmosphere of Venus, where they hit the surface and bounced back to be received by the GBT in a process known as bistatic radar.

This capability is essential to study not only the surface as it appears now, but also to monitor it for changes. By comparing images taken at different periods in time, scientists hope to eventually detect signs of active volcanism or other dynamic geologic processes that could reveal clues to Venus’s geologic history and subsurface conditions.

Links: NRAO press release.

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).