NASA and the European Space Agency have published the results of the rendezvous of the Venus Express and Messenger spacecraft around the planet Venus
The European Space Center's Venus Express research spacecraft and NASA's Messenger research spacecraft met together late in the evening on June 5 this year, around the planet Venus. They observed it together for several hours, photographed it and sent the data to the laboratories on Earth. A few weeks after the event, scientists from the two space agencies publish for the first time the series of photographs from the mysterious planet.
Photograph of the Messenger spacecraft on June 5 this year, following its journey to the planet Hema.
For the video taken by the Messenger spacecraft
The unique opportunity to photograph the atmosphere of the planet Venus was possible thanks to the Messenger research spacecraft. A first step towards continuing its long journey to the planet Hema, while the research spacecraft Venus Express has already circled the planet for a long time and is completing its mission.
Both spacecrafts are equipped with different viewing devices, thus complementing each other. The data provided by the planet Venus is analyzed by teams of the two space agencies on both sides of the ocean. The series of photographs presented in this article already hints at the potential that lies in them for the rest of the results that will be revealed later.
The orbit on which the Venus Express spacecraft circled was in a different location but at the same time when the Messenger spacecraft passed by the planet Venus on June 5.
The gray scale, taken by the VIRTIS spectrometer on the Venus Express spacecraft, shows the atmospheric region of the planet Venus. The same area where the Messenger spacecraft passed on its dark side (marked with a circle).
Photo: European Space Agency.
338 km from the star was the closest point of the Messenger spacecraft to the planet when it is at a point of reference 12.25° South and 165° East, on the dark side of the star. At that time, Venus Express was behind the sunrise almost close to its southern side at a distance of 35,000 km from the star.
If so, how did they manage to monitor those areas? The scientists came up with an original solution.
The cloud hunter
The scientists used a computer simulation based on atmospheric data from the planet Venus, and observations made in the past from Earth and from space. When the wind speed on the planet is known, and thanks to the latitude and longitude lines, the scientists can predict where the clouds will be at a specified time.
From the observations of the Venus Express spacecraft, the team of scientists selected a cloud that moved west about 90° in longitude each day. The cloud was observed by the Venus spacecraft and 12 hours later was observed by the Messenger spacecraft at its closest point to the planet. The same cloud was observed again by the Venus spacecraft 12 hours after the Messenger observation, but while it was on its dark side.
These images were taken by the VIRTIS spectrometer on the Venus Express spacecraft on June 5 and 6 this year, before and after MESSENGER's approach to the planet. This series of photographs provides a glimpse into the dark side of Venus and this is also the same area where the Messenger spacecraft passed. The photograph reveals atmospheric details at a height of 50 km from the surface. Photo: NASA.
The VIRTIS spectrometer on the Venus Express probe examined the cloud by several wavelengths (first row of the series of images above). These observations made it possible to look at the cloud when it is at a longitude of 45-50 km (bottom row). The clouds below the sacrificial point are visible in the top row.
The Mercury Laser Altimeter on the Messenger spacecraft examined the same structure of the cloud at a height of 50-75 km from the surface, as VIRTIS.
Observations of this type are a typical example of the structure of the atmosphere on the planet Venus, when the data comes from other directions and different instruments, and this is a great opportunity for researchers to hope to find answers to the dynamic and complex atmosphere of the planet Venus.
An image from a series of six images from the spectrometer on Venus Express was also taken from the Messenger spacecraft when it passed by the same spot some time later.
Comparison between thermal mapping and radar mapping over the surface of the planet
The photo on the right shows the surface of the planet taken by the Venus Express spacecraft and the photo on the left taken by NASA's Magellan spacecraft from the 90s of the same area. These photographs will help scientists to understand whether the measurement of the temperature on the surface depends only on the altitude - the colder the altitude becomes, the temperature process that exists on Earth - or if it depends on the presence of hot energy sources such as volcanoes.
Photo on the right: European Space Agency.
Photo on the left: NASA.
The Magellan spacecraft radar sent photographs and line-elevation mapping that provided topographical information of the surface. The VIRTIS instrument on Venus Express provided a thermal map of the surface with information on the infrared energy emission. Correlations between topography and thermal data are similar to those seen here and will allow scientists to understand whether the surface temperature measurement is dependent on altitude or other hot sources on the surface such as a volcano or other geological phenomena.
The trajectory of the two research spacecraft - Venus Express and Messenger.
Venus Express orbited the planet Venus from April 11, 2006, until its rendezvous with Messenger this year. This image shows the trajectory of the two spacecraft as well as the observations made from Earth, thus providing a complete scan of the same area at the same time.
The Venus Express and MESSENGER team of scientists are now continuing to analyze all the complex data collected from the planet Venus. The various instruments on the spacecraft do not only provide the data collected on the clouds and the surface, they also provide data related to the environment, magnetic field and the nocturnal glow. Additional results that will be revealed from the many data will be published by the end of the year.
Translation: Yariv Zerbiv
Source - NASA website