Mysterious surface of Venus mapped with Earth-based radar

Chuck Bednar for redOrbit.com – @BednarChuck

The clouds obscuring the surface of Venus can be easily penetrated by spacecraft radar, but now scientists from the National Radio Astronomy Observatory (NRAO) have used powerful ground-based radar technology located here on Earth to create surface maps of the planet.

Building upon research conducted by the Pioneer and Soviet Venera spacecraft in the 1980s and the Magellan spacecraft in the 1990s, the NRAO-affiliated astronomers transmitted radar waves from the Arecibo Observatory in Puerto Rico, bounced them off of the surface of Venus and then received their echoes at the 100-meter Green Bank Telescope (GBT) in West Virginia.

Ain’t their first rodeo

According to Discovery News, the technique was used in 1988, 1999, 2001 and most recently in 2012, allowing scientists to compare the data to search for clues of surface activity on the planet. Their findings are now available online and will be published in the April edition of Icarus.

The signals passed through the atmospheres of both Earth and Venus, where they hit the surface and rebounded to be received by the GBT through a process known as bistatic radar, the NRAO explained. This technique allows experts to study the surface as it currently appears, as well as to compare images taken at different times for sings of active volcanism or other dynamic processes that could provide new insight into the planet’s geologic history and subsurface conditions.

[STORY: Venus may have had seas of carbon dioxide]

“It is painstaking to compare radar images to search for evidence of change, but the work is ongoing,” explained lead author Bruce Campbell, a senior scientist at the Center for Earth and Planetary Studies at the Smithsonian’s National Air and Space Museum in Washington DC.

“In the meantime, combining images from this and an earlier observing period is yielding a wealth of insight about other processes that alter the surface of Venus,” added Campbell, who was assisted on the research by astronomers from Cornell University, NASA’s Goddard Space Flight Center, the Arecibo Observatory and the Smithsonian Astrophysical Observatory.

In the Icarus study, the authors combined the Earth-based radar maps of Venus from both the 1988 and 2012 observations, which featured “inferior conjunctions” that had “similar viewing geometries.” By processing both dataset in order to improve feature detection, they found that the radar images provided “evidence of tessera mantling by impact ejecta,” and that the data can “characterize highlands for remote studies and lander site selection.”

Venus: the baby-faced planet

As Discovery News explained, Venus appears to have a relatively young surface that is covered in both volcanoes and terrain that is ridged and folded. However, the planet appears to have little if any tectonic activity, and it is currently not known if there are any active geological processes at work on the Earth-sized world, which is the second planet from the sun.

[STORY: Zodiacal light visible in Northern Hemisphere this month]

A new image released by the Smithsonian and the NRAO shows the volcanoes and ridges, as well as a unique black diagonal band that led one Gizmodo user to quip that “someone should close that exhaust port, otherwise some pesky X-wing will come along… and blow the whole thing up.” In reality, the band “represents areas too close to the Doppler ‘equator’ to obtain well-resolved image data,” the NRAO explained.

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Source: http://www.redorbit.com/news/space/1113350194/mysterious-surface-of-venus-mapped-with-earth-based-radar-031115/