New images of Ceres. Studying Ceres with the Dawn probe
In the asteroid belt between the orbits of Mars and Jupiter.
Ceres It was discovered on January 1, 1801 by the astronomer Giuseppe Piazzi at the observatory in Palermo, Italy.
Comparative dimensions Ceres, Earth and Moon.
As you can see, the planet Ceres is much smaller than the Moon, and Ceres is the largest planet in the Main Asteroid Belt...
If our Moon were in this belt, it would be a real giant!
And these are the sizes of Ceres and Vesta with the Moon.
They account for 41% of the total mass of the Main Asteroid Belt.
- physical characteristics Equatorial radius - 487.3 ± 1.8 km Polar radius - 454.7 ± 1.6 km Mass (m) - 9.43 ± 0.07 x 1020 kg Average density - 2.077 g / cm 3 Acceleration free fall at the equator - 0.27 m / s 2 (0.028 g) Axis tilt - approx. 3° declination north pole- 59° Albedo - 0.09 ± 0.0033 Spectral class - C Apparent stellar magnitude - from 6.7 to 9.32 Absolute magnitude - 3.36 ± 0.02 Angular Diameter - 0.84" to 0.33" |
- characteristics of the orbit: Perihelion - 381,028,000 km (2.5465 AU) Aphelion - 446,521,000 km (2.9842 AU) Semi-major axis (a) - 413,767,000 km (2.7653 AU) Orbital eccentricity (e) - 0.07934 Sidereal circulation period - 1680.5 days (4.60 Earth years) Orbital speed (v) - 17.882 km/s Inclination to the Ecliptic (i) - 10.585° |
It is the largest body in the asteroid belt between Jupiter and Mars. According to calculations, Ceres accounts for 32% of the mass of this asteroid belt. The planet Ceres is placed in the recently identified class of dwarf planets along with Pluto, Haumea, Makemake, and Eris. It is the smallest of them. Dwarf planets are distinguished, among other things, by the fact that they have enough mass to give themselves a spherical shape under the influence of their own gravity.
It is assumed that planet Ceres has a stone core, an icy mantle, and a thin layer of regolith on the surface. Moreover, the mantle consists of water ice, which makes up to 20-30% of the mass of Ceres.
According to some estimates, Ceres contains about 200 million km³ of water in the form of ice. This is 1/10 of the volume of the earth's oceans and more than the earth's reserves fresh water.
Ceres is one of the most promising sites for colonization in the distant future:
* Ceres has a very low gravity, that is, takeoff and landing are greatly facilitated spaceships;
* Large reserves of water ice will provide the colony with water, fuel and air (water splits into hydrogen and oxygen)
* Ceres is a convenient base for exploring the systems of the giant planets, due to its convenient location between the Inner and Outer planets.
But there are also difficulties:
* Not on Ceres magnetic field which will adversely affect human health
* Low temperatures due to small quantities sunlight
* There is not even a weak atmosphere that could partially protect at least from the smallest dust-like meteorites;
* Main belt asteroids pose a danger to ships
It is quite possible to see Ceres through a telescope - the brightness can reach about 7 magnitudes, but to consider the details - alas.
Even the image of Ceres from the Hubble telescope looked rather modest. And this is taking into account its power in the absence of atmospheric distortion. Until recently Ceres studied only with the help of telescops, including radio telescopes, which showed that the surface of Ceres is relatively smooth.
That's why, big hopes were assigned to NASA's "Down" ("Dawn"), which was launched on September 27, 2007 after numerous delays.
In 2011, the Dawn spacecraft went into orbit around Vesta and then headed towards Ceres.
Dawn entered the orbit of Ceres on March 6, 2015 and met the expectations of earthlings, starting a series of images, gradually descending over the planet.
Here is a short June video of the results of photography. Approximately 80 individual shots used.
On June 3, 2015, Rassvet entered an orbit of 4400 km. and started new series pictures to be taken by June 28th.
The clarity of the images has increased markedly, the spots have broken up into separate parts that previously merged into one. A sharp black line became more noticeable, "stuck" into the central light spot "from the bottom right". This line looks like a defect in the image, but in the earlier picture it was already present in this place.
But still the spots remain a mystery. So far, this is the best image of spots on Ceres.
Video from NASA posted on August 6th. This is a video of a three-dimensional model of the surface of Ceres, more precisely, two of its regions - with incomprehensible bright spots and an area with a high pointed mountain, a peak about 6 km high above the surrounding surface:
Video from NASA posted on September 9th. A computer model of the Occator crater on Ceres, in which those very bright spots are located:
On September 9th, new images of bright spots in the Occator crater were posted.
The resolution was 140 meters per point.
The pictures were taken from a height of 1470 km.
The walls of Occator are curious - in some places they reach a height of two kilometers and at the same time are completely sheer.
Alas, the new pictures so far have not particularly clarified anything. On the other hand, these spots have little resemblance to the lights of alien cities.
We are waiting for the further descent of the Dawn apparatus - the next series of images will be taken from an orbit of 375 kilometers.
Video from NASA posted on January 29, 2016.
Video based on images from a height of 1450 km. from August to October 2015.
On June 29, 2016, researchers announced that, according to new data, sodium carbonate is the main mineral of Ceres' mysterious bright area in the Occator crater. On Earth, it is most commonly found in hydrothermal vents. This suggests hydrothermal activity on Ceres in the past.
The highest mountain on Ceres - Ahuna Mons (Ahuna Mons), is a cryovolcano with a height of 5 kilometers.
See the current position of Ceres and other most notable celestial bodies on the Sky Map page online. More on this topic:
Asteroid Vesta
Eris - dwarf planet
As it approaches Ceres, Dawn makes more and more discoveries. Following the bright spots on the surface of the dwarf planet, the spacecraft discovered a pyramid-shaped mountain. The new photos were taken from a distance of 4400 kilometers.
Just six months ago, Ceres was observed as a few pixels. Now Dawn is approaching the dwarf planet as close as possible. By December this year, the spacecraft will be just 360 kilometers above the surface of Ceres, below the flight altitude of the International space station above the Earth, writes the British newspaper Daily Mail.
It is noteworthy that the pyramidal mountain rises above a relatively flat surface. In height, this hill is comparable to the Mont Blanc massif between France and Italy. Mont Blanc, whose height reaches 4810 meters, is the highest mountain in Europe.
Another photo shows a few more bright spots. The diameter of the largest of the detected bright spots is about nine kilometers. Scientists are inclined to believe that these areas are formed by the reflection of sunlight by salt and ice.
The first mysterious spot Dawn spotted a few months ago. As they approached the planet, their number began to grow. Researchers have already managed to count up to eight spots. In fact, there may be even more.
Other images show areas with many lines and craters scattered across the surface of Ceres, located in the asteroid belt between Mars and Jupiter. Landslides and destroyed structures of natural origin also testify to the activity on its surface in the past.
Dawn arrived at Ceres on March 6, 2015, and is the first spacecraft to visit the orbits of two separate celestial bodies in the solar system. Prior to that, he studied the protoplanet Vesta.
Dawn will remain in its current orbit until June 30th. In early August, he and Ceres will be separated by a distance of only 1450 kilometers.
Ceres was discovered on January 1, 1801 by the Italian Giuseppe Piazzi. It is the only asteroid belt object that can be seen with the naked eye under certain conditions.
Ceres in 2006 was qualified as a dwarf planet, that is, such a celestial body, the dimensions of which allow it, under the influence of internal forces, to take a shape close to spherical. It is very important that the study of Ceres by the Dawn probe will be carried out with the same equipment as Vesta, and therefore the results obtained will be easily comparable with each other.
Surface map
Research program
In the process of researching Ceres, all the equipment available at the station, previously used in the study of Vesta, will be involved. These are photographic equipment, a spectrograph and a radiation detector. In addition, with the help of radio measurements, the gravitational field of a celestial body will be estimated, which will make it possible to determine the change in density inside it and thus determine whether Ceres has a metallic core. In the lowest orbit will be tested new method control of the apparatus, called "hybrid", with the help of flywheel engines similar to a gyroscope. The goal of the experiment is to save hydrazine for emergency use.
Approximate study schedule
According to the plans of scientists, the spacecraft will fall into the Ceres gravity zone in early April 2015. Having approached 4430 km and entered a circular orbit, the station will begin a 22-day program to study the dwarf planet. Then there will be a decrease to 1480 km and work will continue. The lowest orbit to which it is planned to lower aircraft, is approximately 375 km. The probe should spend about three months on it. Further, the situation will develop depending on the accuracy of the implementation of the previous stages, the presence of hydrazine in the fuel tanks and the remaining electricity reserve of the nickel-hydrogen battery.
Photographing
Photographing a celestial body will begin as soon as the aircraft approaches it at a distance of 13,500 km. Already from this height, Ceres looks 8 times larger than the Moon. Research is activated when the space probe descends into lower circular orbits. Sequential photography, first from a height of 4430 km, then - 1480 and on final stage- 375 km, which will be held for almost six months, will allow you to create an initial overview, and then a detailed map of all parts of the dwarf planet. During this time, thousands of photographs will be taken, which will gradually be transmitted to Earth.
Data transmission to Earth
Deep SpaceNetwork Antenna Gallery.
The spacecraft will begin communication with the Earth as soon as the first information for transmission appears. Data will be sent selectively, viewed in the control center, and only after that a command will be given to send the rest. This is done in order to get the most up-to-date information in the first place. The data will be pre-compressed, as the transfer rate is low by earthly standards. In addition, the design bit rate (41-128 kbit/s) may become significantly lower due to technical problems, as was already the case in the Vesta area. Then the main antenna failed, but the scientists managed to restore its performance. The largest and most powerful deep space communication system, Deep SpaceNetwork, will receive data from the probe.
Special Expectations
A number of scientists suggest that Ceres is 25% water, which exceeds all available terrestrial reserves, and some of it may be in the liquid phase under a 100-kilometer thickness of ice. So far, this is a hypothesis, but it is not long before it is confirmed or refuted. celestial bodies having liquid water, until now, scientists have not been able to find, which naturally fuels interest in the expedition of the Dawn space probe. The presence of large reserves of ice on the way to other planets solar system opens the possibility of its use for the needs of future manned expeditions.
NASA's Dawn spacecraft sent back images of the dwarf planet Ceres taken from as close as possible. They show previously unknown details of the relief, including a high cone-shaped mountain with signs of crater origin, entangled in a network of cracks.
A shot of the cone-shaped mountain from a distance of 1,470 km. Southern hemisphere, height 6 km. The perimeter is clearly outlined, and there are practically no rock fragments near the cracked slopes. Photo by NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
"Dawn" works flawlessly in the new orbit. Now it sends back three times sharper images, revealing new features of this dwarf planet,” shares Mark Rayman, chief designer unit and head of its mission from the NASA Jet Propulsion Laboratory, located in Pasadena, California.
Bottom left is the mountain range in the center of the Urvara crater on Ceres. Photo by NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
A picture of the Gaue crater from the Rassvet apparatus. Gaue is a German goddess to whom offerings were made during the wheat harvest. Photo by NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
The new orbit of the Rassvet movement is located 1470 km above Ceres. It takes him 11 days to capture the entire surface of the planet and send the images back to Earth. During this time, he makes 14 revolutions around the dwarf. Over the next two months, he will do this work 6 times.
To create an extensive map of the surface of Ceres, Rassvet uses a frame camera, which allows 3D image modeling. Its resolution is 140 meters per pixel. One image captures less than 1% of the entire surface of the planet. At the same time, spectrometers for infrared and visible radiation operate on the apparatus. With their help, photographs are taken, according to which scientists analyze the mineral composition of the planet's surface.
The researchers also intend to make more accurate measurements of Ceres' gravitational field to calculate the next, lower (375 km) orbit of the device, the transition to which is planned for the end of October this year. Dawn is the first spacecraft sent to a dwarf planet. He was also the first to be given the task of exploring two different objects in the solar system. In 2011-2012, he orbited the protoplanet Vesta for 14 months, and on March 6, 2015 he reached Ceres.
Ceres is the largest asteroid in the asteroid belt and has achieved dwarf planet status. The race to discover this planet still began in 1781, at the time when the planet Uranus was discovered, located in the very region of space in space that belonged to the Titius-Bode rule. The rule of Titius (German scientist) proves the regularity of the increase in the increase in the radii of the orbits of the planets located near the Sun. Some time later, this rule turned out to be inaccurate, and the discovery of Uranus in the same place gave rise to an avid "hunt for the planets" among astronomers of past centuries.
Discovery history
Later, in 1800, an international group of scientists - astronomers "Heavenly Guard" was founded. Around the clock, she conducted observations of the space in space between the orbits of Jupiter and Mars, that is, in the area where that still undiscovered planet should have been located. Ceres was discovered in this area by the Italian astronomer Giuseppe Piazzi in 1801. At first he mistook her for a comet, but nevertheless noticed that she had some peculiarities. Throughout the year, attempts to fix the existence of this asteroid planet were made by other scientists, but only on the last day of 1801 did they manage to confirm its existence. With this, the Titius-Bode rule again acquired justice. Giuseppe Piazzi himself called the asteroid planet "Ceres", although before that it was pronounced as "Ceres Ferdinand".
In 1802, Ceres was classified as an asteroid. The largest cosmic body in the main asteroid belt has a diameter of 950 kilometers, has the shape of a sphere, which arose due to the presence of Ceres of its own gravity, and six thousand times less mass than the Earth has, and at the same time it makes up a third of the total mass of objects asteroid belts.
According to scientists, after the asteroid Ceres acquired a spherical shape, processes of gradual displacement into central part the heaviest breeds. The result of this displacement was the formation of a stone core. Water ice makes up the outer shell, which is about 100 kilometers thick, more than Earth's fresh water supply.
Research
Ceres is one of the main participants, with good prospects, in the projected space developments. First of all, this is due to the fact that it stores a huge supply of fresh water, and this fact may serve as the opportunity to create life here.
In terms of colonization, Ceres is of great interest. At the second stage of space exploration, they plan to colonize Ceres. At the first stage, they expect to colonize space objects located relatively close to the Earth, the Moon, Venus, Mars, and Mercury.
distant future
Ceres lies between the gas giants and the planets terrestrial group”, has good conditions, allowing it to serve as an ideal transshipment point for the creation of space bases on it. The negative factors of this planet include low gravity and the absence of a magnetic field, which is a negative factor for human health.
Flight animation spacecraft DAWN from Vesta to Ceres