Dawn spacecraft belonging to the US space agency NASA provides continuous shots dwarf planet Ceres. Scientists most intriguing bright spots, which are located on the surface of the crater with a diameter of 100 km. Dawn spacecraft, which since the end of April this year, closely following Ceres, sent us a photo sequence of 3 and 4 May 2015 year. She made it from a distance of 13 600 km.
Uploaded images show more accurately the topography of the dwarf planet. You see, among others, white spots, which are a great crater with a diameter of 100 km on the surface of Ceres. The researchers speculate that they may also be impact craters. The largest spot has a diameter of about 13 km. Around it are smaller.
– We can not state clearly what is their nature. They are intensely bright due to the reflection of sunlight on the surface of a highly reflective. The sun’s rays have to bounce from a very reflective material, possibly ice – said Christopher Russell, Dawn principal scientist for the mission at California University in Los Angeles.Transferred images give scientists more information about shapes and sizes. The image resolution is 1.3 kilometers per pixel.
Dawn needed 7.5 years to reach the asteroid. In late April, he joined the study. The program envisages that as research progresses’s orbit will be gradually reduced so that in the end she found at an altitude of only a few hundred kilometers above the surface of the asteroid. The probe is to conduct research for at least 14 months. As the depletion of fuel reserves, the probe will lose the opportunity to conduct research and directing the antenna toward Earth. Will continue to revolve around Ceres, but do not fall on the surface for at least the next 100 years.
Ceres is a unique object in our solar system. It is a dwarf planet that circulates inside the asteroid belt between the orbits of Mars and Jupiter. It has a diameter of 950 km and is the largest of the bodies circulating inside of the belt. It was discovered in 1801 by Italian astronomer Giuseppe Piazzi. Initially, it was defined as a planet, after decades began to define it as a planetoid. In August 2006, we introduced the term dwarf planet Ceres and was included in the group of objects. Ceres intrigues scientists because its interior consists of a sizable nucleus of rock, and it extends over a layer of water ice and a thin outer shell made of light materials. Scientists suspect that 25 percent of Ceres weight is water, and it would mean that no more fresh water than Earth. There has been also exploding plumes of water vapor from the surface of asteroids that can come from geysers.
The mysterious white spots aroused a sensation from the first moment when they saw a few months ago it on photographs of the probe, which flew the first mission of research into this planet. The spots are inside the crater about 80 km in diameter.
Dawn spacecraft has sent new pictures of Ceres with a very short distance of 13.5 thousand. km. In the pictures, it turned out that there are two mysterious white spots. Subsequent images captured by the probe showed that the spots split into smaller parts.
For the latest patches resemble a mosaic of pictures of many bright objects whose edges are irregular, ragged even that is really a mosaic of many, at least 10 spots, and they are not regular (their edges are ragged).
Ceres surface is very dark, reflecting an average of only 10 percent. incident light (for comparison – one-third of the Earth reflects light). Therefore, these bright spots so tight they beat the eyes. Scientists still do not know what they are.
An internal survey, which in their midst NASA researchers conducted the Jet Propulsion Laboratory in Pasadena, showed that opinions are divided. 30 percent. one is inclined to the fact that it actually ice. But more – because 37 percent. – He believes that the explanation is „other”.
The presence of outdoor expanses of ice on the surface of Ceres would be surprising, because ice in the absence of the atmosphere is unstable – it should sublimate and fairly quickly escape into space. Perhaps the witness of this process was the Herschel space telescope, which last year noticed a cloud of water vapor over the Ceres. Mark Sykes of the Planetary Science Institute supposes that white patches are not made of pure ice. In his opinion, this sediment with salt, which remained after the mineral-rich water ice has evaporated.
Ceres has a relatively small average thickness, which suggests that its interior is largely ice. Mike Brown, an astronomer at Caltech in Pasadena, believes ice deposits are quite shallow beneath the dust and revealing by the impact of meteorites or comets. Because these bright spots, which at the moment are focused all the attention, they are not the only ones. The area is covered asteroids larger number of bright spots and areas.
The researchers also spotted gaps and clefts, which may mean that the globe is still (or until recently was) active geologically. May 9 Dawn turned its ion engines and began a spiral descent even lower orbit. June 6 will be 4.4 thousand. km above the surface, and so it will be circled three times lower than now. But we will not have to wait for more messages until a month because the way the probe has twice stopped (ie. Disable the engines) to execute and send us new photos.
It also has an on-board instrument that will study the mineral composition of rocks on the surface, so soon we should find out what’s out there so shines.
Source: tvnmeteo. tvn24.pl, gazeta.pl, pl.wikipedia.org, nautilus.org.pl, NASA, Scientific American