 |
|
Mars and Venus are surprisingly similar
March 06, 2008Using two ESA spacecraft, planetary scientists are watching the atmospheres of Mars and Venus being stripped away into space. The simultaneous observations by Mars Express and Venus Express give scientists the data they need to investigate the evolution of the two planets' atmospheres.
Scientists call this work comparative planetology. Mars Express and Venus Express are so good at it because they carry very similar science instruments. In the case of the Analyser of Space Plasmas and Energetic Atoms (ASPERA), they are virtually identical. This allows scientists to make direct comparisons between the two planets.
The new results probe directly into the magnetic regions behind the planets, which are the predominant channels through which electrically-charged particles escape. They also present the first detection of whole atoms escaping from the atmosphere of Venus, and show that the rate of escape rose by ten times on Mars when a solar storm struck in December 2006.
By observing the current rates of loss of the two atmospheres, planetary scientists hope that they will be able to turn back the clock and understand what they were like in the past. "These results give us the potential to measure the evolution of planetary climates," says David Brain, Supporting Investigator for plasma physics for Venus Express and Co-Investigator for ASPERA on Mars and Venus Express at the University of California, Berkeley.
The new observations show that, despite the differences in size and distance from the Sun, Mars and Venus are surprisingly similar. Both planets have beams of electrically charged particles flowing out of their atmospheres. The particles are being accelerated away by interactions with the solar wind, a constant stream of electrically charged particles released by the Sun.
At Earth, the solar wind does not directly interact with the atmosphere. It is diverted by Earth's natural cloak of magnetism. Neither Mars nor Venus have appreciable magnetic fields generated inside the planet, so each planet's atmosphere suffers the full impact of the solar wind.
Interestingly, this full-on interaction does create a weak magnetic field that drapes itself around each planet and stretches out behind the night-side in a long tail. Venus's atmosphere is thick and dense, whereas that of Mars is light and tenuous. Despite the differences, the magnetometer instruments have discovered that the structure of the magnetic fields of both planets are alike.
"This is because the density of the ionosphere at 250 km altitude is surprisingly similar," says Tielong Zhang, Principal Investigator for the Venus Express magnetometer instrument at Institut für Weltraumforschung (IWF), Österreiche Akademie der Wissenschaften, Austria. The ionosphere is the surrounding shell of electrically-charged particles created by the impact of sunlight on the planet's upper atmosphere.
The proximity of Venus to the Sun does create an important difference, however. The solar wind thins out as it moves through space so the closer to the Sun it is encountered, the more concentrated is its force. This creates a stronger magnetic field, making the escaping atmospheric particles move collectively like a fluid.
At Mars, the weaker field means that the escaping particles act as individuals. "This is a fundamental difference between the two planets," says Stas Barabash, ASPERA Principal Investigator on both Mars Express and Venus Express, Swedish Institute of Space Physics.
Another illuminating difference between Mars and Venus is that Mars displays strong small-scale magnetic fields locked into the crust of the planet. In some regions, these pockets protect the atmosphere, in others they actually help funnel the atmosphere into space.
The complexity of the different processes revealed at Venus and Mars means that planetary scientists do not yet have the full picture. "There will be many more results to come," says Barabash.
There is a lot to do because there are many different mechanisms that may cause the atmospheric particles to escape. Untangling it all will take time. "The longer the spacecraft work together, the longer we can watch and see what really happens," says Brain.
European Space Agency
The new observations show that, despite the differences in size and distance from the Sun, Mars and Venus are surprisingly similar. Both planets have beams of electrically charged particles flowing out of their atmospheres. The particles are being accelerated away by interactions with the solar wind, a constant stream of electrically charged particles released by the Sun.
At Earth, the solar wind does not directly interact with the atmosphere. It is diverted by Earth's natural cloak of magnetism. Neither Mars nor Venus have appreciable magnetic fields generated inside the planet, so each planet's atmosphere suffers the full impact of the solar wind.
Interestingly, this full-on interaction does create a weak magnetic field that drapes itself around each planet and stretches out behind the night-side in a long tail. Venus's atmosphere is thick and dense, whereas that of Mars is light and tenuous. Despite the differences, the magnetometer instruments have discovered that the structure of the magnetic fields of both planets are alike.
"This is because the density of the ionosphere at 250 km altitude is surprisingly similar," says Tielong Zhang, Principal Investigator for the Venus Express magnetometer instrument at Institut für Weltraumforschung (IWF), Österreiche Akademie der Wissenschaften, Austria. The ionosphere is the surrounding shell of electrically-charged particles created by the impact of sunlight on the planet's upper atmosphere.
The proximity of Venus to the Sun does create an important difference, however. The solar wind thins out as it moves through space so the closer to the Sun it is encountered, the more concentrated is its force. This creates a stronger magnetic field, making the escaping atmospheric particles move collectively like a fluid.
At Mars, the weaker field means that the escaping particles act as individuals. "This is a fundamental difference between the two planets," says Stas Barabash, ASPERA Principal Investigator on both Mars Express and Venus Express, Swedish Institute of Space Physics.
Another illuminating difference between Mars and Venus is that Mars displays strong small-scale magnetic fields locked into the crust of the planet. In some regions, these pockets protect the atmosphere, in others they actually help funnel the atmosphere into space.
The complexity of the different processes revealed at Venus and Mars means that planetary scientists do not yet have the full picture. "There will be many more results to come," says Barabash.
There is a lot to do because there are many different mechanisms that may cause the atmospheric particles to escape. Untangling it all will take time. "The longer the spacecraft work together, the longer we can watch and see what really happens," says Brain.
European Space Agency
Venus Express Current Events and Venus Express News RSSNew map hints at Venus's wet, volcanic past
Venus Express has charted the first map of Venus's southern hemisphere at infrared wavelengths. The new map hints that our neighbouring world may once have been more Earth-like, with both, a plate tectonics system and an ocean of water.
Where did Venus's water go?
Venus Express has made the first detection of an atmospheric loss process on Venus's day-side. Last year, the spacecraft revealed that most of the lost atmosphere escapes from the night-side.
Venus comes to life at wavelengths invisible to human eyes
A pale yellow-green dot to the human eye, Earth's twin planet comes to life in the ultraviolet and the infrared. New images taken by instruments on board ESA's Venus Express provide insight into the turbulent atmosphere of our neighbouring planet.
Key molecule discovered in Venus's atmosphere
Venus Express has detected the molecule hydroxyl on another planet for the first time. This detection gives scientists an important new tool to unlock the workings of Venus's dense atmosphere.
Plan to identify watery Earth-like planets develops
Astronomers are looking to identify Earth-like watery worlds circling distant stars from a glint of light seen through an optical space telescope and a mathematical method developed by researchers at Penn State and the University of Hawaii.
Venus Express reboots the search for active volcanoes on Venus
ESA's Venus Express has measured a highly variable quantity of the volcanic gas sulphur dioxide in the atmosphere of Venus. Scientists must now decide whether this is evidence for active volcanoes on Venus, or linked to a hitherto unknown mechanism affecting the upper atmosphere.
The light and dark of Venus
Venus Express has revealed a planet of extraordinarily changeable and extremely large-scale weather. Bright hazes appear in a matter of days, reaching from the south pole to the low southern latitudes and disappearing just as quickly.
Basque Country University researchers publish two articles in Nature on latest discoveries on Venus
Nature journal has published a series of articles devoted to the new discoveries by the European Space Agency's (ESA) Venus Express space probe made on our neighbouring planet.
Setting stars reveal planetary secrets
Watching the stars set from the surface of the Earth may be a romantic pastime but when a spacecraft does it from orbit, it can reveal hidden details about a planet's atmosphere.
New isotope molecule may add to Venus' greenhouse effect
Planetary scientists on both sides of the Atlantic have tracked down a rare molecule in the atmospheres of both Mars and Venus. The molecule, an exotic form of carbon dioxide, could affect the way the greenhouse mechanism works on Venus.
More Venus Express Current Events and Venus Express News Articles
 |
Venus Express (Original Mix) Stefan Tretau (Primary Contributor) |
 |
Colonization of Venus: Venus, Bone decalcification, Venus Express, Terraforming of Venus, Venera 5, Venera 6, Venera 7, Venera 8, Venera 9, Venera 10, ... Venera 14, Skyhook (structure), Vega program by John McBrewster (Editor), Frederic P. Miller (Editor), Agnes F. Vandome (Editor) Colonization of Venus - Venus, Bone decalcification, Venus Express, Terraforming of Venus, Venera 5, Venera 6, Venera 7, Venera 8, Venera 9, Venera 10, Venera 11, Venera 12, Venera 13, Venera 14, Skyhook (structure), Vega program |
|
Bialetti Venus, Moka Express Coffee Maker 4 Cup by Bialetti Espresso coffee maker made with 18/10 stainless steel. The handle and lid are ergonomic and covered in heat proof material. Makes a perfet gift! | |
 |
#10 Regular Envelope - Astrobright Venus Violet ( 4 1/8 x 9 1/2) (250) by Office Express A Quantity of 250 - #10 Venus Violet Regular Envelope - 24# Astobright Venus Violet Paper. This is made from Wausau Astrobright Venus Violet Paper. Venus Violet papers are made water soluable dyes. Consistant color makes these perfect for advertisements, brochures or even Greeting Cards. Use this envelope with a handmade card or note to ensure you get attention. |
 |
TENNIS EXPRESS Venus vs Serena Major Match Up-- by TENNIS EXPRESS Rare and collectible NETPRO limited edition Major Match-Up Card featuring Serena Williams on one side and Venus Williams on the other side. Collect all 4 Major Match-Up Cards: Agassi vs. Sampras Roddick vs. Federer Venus vs. Serena Hingis vs. Kournikova |
 |
Wilson Venus & Serena 21" Youth Tennis Racket by Wilson WILSON Venus & Serena 21" Racket features Volcanic Frame Technology for power and stability. Titanium Alloy for lightweight strength. Bumper guard extends racket life. 95" Midplus head size. Average strung weight 6.2 oz. 3 1/2" grip. |
![Marlene Dietrich 6 Disc Box Set ( Shanghai Express / Destry Rides Again / The Devil Is a Woman / A Foreign Affair / Blonde Venus / The Lady Is Willing ) [ NON-USA FORMAT, PAL, Reg.2.4 Import - Great Britain ]](http://ecx.images-amazon.com/images/I/41FIg4GXBtL._SL160_.jpg) |
Marlene Dietrich 6 Disc Box Set ( Shanghai Express / Destry Rides Again / The Devil Is a Woman / A Foreign Affair / Blonde Venus / The Lady Is Willing ) [ NON-USA FORMAT, PAL, Reg.2.4 Import - Great Britain ] Directed By: Billy Wilder, George Marshall, Josef von Sternberg, Mitchell Leisen Also With: Anna May Wong (Primary Contributor), Brian Donlevy (Primary Contributor), Cary Grant (Primary Contributor), Clive Brook (Primary Contributor), Eugene Pallette (Primary Contributor), James Stewart (Primary Contributor), Joel McCrea (Primary Contributor), Lawrence Grant (Primary Contributor), Marlene Dietrich (Primary Contributor), Warner Oland (Primary Contributor), CategoryArthouse (Commentary), CategoryClassicFilms (Commentary), CategoryUSA (Commentary), film movie Classic (Commentary) Great Britain released, PAL/Region 2.4 DVD: it WILL NOT play on standard US DVD player. You need multi-region PAL/NTSC DVD player to view it in USA/Canada: LANGUAGES: English ( Mono ), English ( Subtitles ), SPECIAL FEATURES: Interactive Menu, Scene Access, SYNOPSIS: Shanghai Express;;As China's great train, the Shanghai Express, is being boarded and loaded with baggage, a mixed assortment of characters run elbows, a lady of questionable reputation known as the White Flower of the Chinese coast; a British Medical Corps officer; Warner Oland, a shady half-caste merchant with a penchant for carrying a cane; and Anna Mae Wong, an American-bred Chinese prostitute with plans for starting anew in marriage. The time of the journey is one of great political unrest, with the possibility of bands... |
 |
Womens Designer Perfume by Vicky Tiel, ( VENUS DE L'AMOUR EAU DE TOILETTE SPRAY 3.3 oz. TESTER + On Sale ) - @Up To 81% Off by Vicky Tiel |
|
Living on the Venus Express by Spoonface | |
 |
Venus De L'amour By Vicky Tiel For Women. Eau De Toilette Spray 1.7 Ounces by Vicky Tiel Introduced in 1997. Fragrance notes: a floral blend of exotic spices, citrus, amber and vanilla. Recommended use: romantic. |
| © 2009 BrightSurf.com |