by • March 22, 2016 • No Comments
Dawn’s science team has presented a treasure trove of data and images captured by the spacecraft as it orbits a mere 240 miles (385 km) above the surface of the dwarf planet Ceres. The observations, which include a stunningly additional detailed view of the famous Occator crater, are major to a series of breakthroughs regarding the nature of the enigmatic wanderer which include the initially detection of ice water on the planetoid’s surface.
As always, we’ll start with the Occator crater. Spanning an astounding 57 miles (92 km), the impact site is believed to be one of the youngest of the sizeable craters scarring the surface of Ceres, with astronomers estimating its age at 80 million years. The composite image displays in satisfactory additional detail a gentle dome in the white covered centre of the crater inside a walled pit, and well as a host of fractures lining the basin of the showcase.
The fractures are believed to be the hallmarks of new geological activity. Naturally, the image is dominated by the bright blemishes of what is now believed to be a kind of salt, not far removed of epsom salts found here on planet Earth, which shine in stark contrast to their dull surroundings.
Much of the data returned by Dawn hints at a subsurface layer of ice and volatile materials. A color-enhanced map of Ceres contained in the new release, highlights the distribution of impact sites and the surprising diversity of surface materials.
An enhanced color elliptical map of Ceres – the image boasts a resolution of 460 ft (140 m) per pixel, and comes with infrared wavelengths of light ordinarily invisible to the naked eye
Most interestingly, Dawn’s science team has observed sure color variations which are believed to occur as a outcome of surface effects dredging up a subsurface layer of ice and volatile materials. The team believe which the surface composition surrounding a few impact sites, such as the Haulani crater, may have additional altered the properties of the exhumed materials.
Further evidence for the existence of a subsurface layer of ice, which had been one of the major theory accounting for the existence of bright deposits on Ceres surface was provided by Dawn’s Gamma Ray and Neuron Detector (GRaND) instrument.
GRaND was created to map the interaction between cosmic rays and the dwarf planet’s desolate surface in order to divine the chemical manufacture-up of Ceres’ uppermost meter of regolith. Upon analyzing the data collected by GRaND, the team found which whilst there was an abundance of neutrons at the dwarf planet’s equator, the population of the subatomic particles at the polls was comparatively scarce.
Map of Ceres displaying the distribution of hydrogen, represented in blue, and neutrons, which are represented in red
According to the team, this imbalance suggests the presence of worthwhile quantities of hydrogen located at a lower place the surface near Ceres’ polar regions. As hydrogen accounts for two of the three molecules which manufacture up H2O, the team are thinking this a positive indicator for the presence of water ice buried at a lower place the surface.
Whilst GRaND hunted for oblique evidence of a buried layer of water ice, Dawn’s visible and infrared mapping spectrometer (VIR) created the initially detection of water on Ceres’ surface. The signature was detected in a 6 mile (9 km)-wide impact site known as Oxo crater, which is located in Ceres’ northern hemisphere. Oxo represents the 2nd brightest showcase present on Ceres’ surface, with the Occator crater remaining the brightest.
It is idea which the water was uncovered either due to the impact or thanks to a additional new landslide, and it is not yet known whether the water exists in ice form or if it is bound in minerals.
by admin • March 5, 2017
by admin • November 28, 2016
by admin • November 28, 2016