Launched in 2006 to explore (considered a full-fledged, and now bearing the “title” of a dwarf) planet of the solar system, Pluto, the mission “honorably completed the task and is forever moving away from its native star. What are the results of the research carried out by the automatic interplanetary station?
Scientists astronomers were looking forward to the meeting of the apparatus with Pluto, since not a single creation of human hands had come close to it before. Data on the planet, named after the god of the underworld of the dead, revered by the ancient Romans, previously available to astrophysicists are materials obtained from ground-based telescopes, as well as from an orbiting telescope.
After the flight of the device over the surface of Pluto, a huge amount of information received as a result of scanning the planet is stored in the memory of the device. Given the unprecedented remoteness of the "New Horizons" from the Earth, the data transfer rate is severely limited. And the station is removed by more than 40 (one astronomical unit - AU is equal to the distance from the Earth to the Sun 150 million kilometers). Therefore, information from the memory disks of the research mission was transmitted to Earth only about a year later.
As it turned out, Pluto was in vain considered a dead piece of ice and frozen gases. Space research has shown that this is not the case. Comparing the surface of a dwarf planet with the surface of its natural satellite Charon (in the beliefs of the ancient Romans, Charon is a boatman transporting the souls of dead people to the realm of shadows through the sacred river Styx), one cannot fail to notice striking differences. Among them - an extremely small number of meteorite craters on Pluto compared to the satellite.
This can have only one explanation - the surface of the planetoid is constantly updated as a result of processes occurring in the bowels. All planets in the solar system that have a mass sufficient for hydrostatic equilibrium have similar processes.
On Earth, it looks like this: tectonic plates of solid rock “float” on the surface of the molten mantle. These plates expand, shrink, collide, causing earthquakes and volcanic eruptions. On Pluto, the tectonic plates are composed of water ice as well as frozen gases and rest on a substance of the same material, but fluid under the pressure of the upper layers.
Across the surface of Pluto, the results of tectonics are observed: icy mountain ranges and ridges, smooth plains of recently frozen gases and liquids, as well as cryovolcanoes. They differ from terrestrial volcanoes in that water vapor and other gases erupt from them, and the same substances in liquid form flow down the slopes.
The composition of ice and the atmosphere of Pluto
Space research has shown that Pluto's surface is dominated by water and nitrogen ice. These two components are unevenly distributed over the surface of the planet, and this may be the key to understanding tectonic processes. In addition, the plains are covered with a layer of tholins - polymerized simple hydrocarbons. These substances are formed from the original methane and ethane under the influence of ultraviolet rays, the source of which is the Sun.
Under the physical conditions of deep space, tholins crystallize, their masses have a yellow-brown color. It is thanks to these chemical compounds that Pluto's surface has a slightly unusual, relatively bright color.
But the atmosphere of the planetoid let us down. Scientists hoped to find a denser and more powerful atmosphere than the one found by an automatic interplanetary station. The pressure of the atmosphere at the surface is not more than one hundred thousandth of the earth's. As you know, Pluto's orbit is highly elongated, and has a very significant eccentricity: at perihelion, the planet is almost two (!) Times closer to the Sun than at apogee, and it receives almost three times more light at the point closest to the star.
This feature most likely results in significant changes in atmospheric density depending on the time of the Plutonian year. But it will not be possible to test this hypothesis in the near future through observations, since the period of revolution of Pluto around the Sun is 248 Earth years.
The atmosphere consists mainly of nitrogen, methane is also present in small quantities, traces of carbon monoxide appear. Tolins are most likely formed precisely in the atmosphere, then, condensing, they fall to the surface in a thin layer. And before they fall, the tholins are in suspension, forming a kind of clouds, which were discovered by the spacecraft.
satellites
Pluto's first discovered moon is Charon. He was back in the eighties of the last century. Charon is the largest natural satellite of a planetoid and the only one with a mass sufficient to achieve hydrostatic equilibrium. Interestingly, the ratio of the mass of the planet and the satellite is 1 to 8. This is a very large mass of the satellite in relation to the mass of the mother planet. Because of this, the Pluto-Charon pair was sometimes called a double planet.
Fly over Charon
The surface of Charon is covered mainly with water ice, there is evidence of geological activity of the celestial body, in particular cryovolcanoes. True, it is much weaker than on Pluto.
The remaining satellites of the planetoid are Styx, Nikta, Kerberos (Cerberus) and Hydra. These are irregularly shaped pieces of rock less than a hundred kilometers in size.
What are the horizons "beyond the horizon"
After leaving the Pluto system, the automatic interplanetary station continues to move away from the Sun at a speed of about 15 kilometers per second. It is planned that on the night of December 31, 2018 to January 1, 2019, the device will have a "New Year's" meeting in the Kuiper belt with one of its classic representatives - a small asteroid 2014MU-69. Then the transmission of the received data will follow, and in the 20s of the current millennium, the mission will finally be completed.
> Chronology
launch vehicle: Atlas V 551 first stage; Centaur second stage; STAR 48B third stage
Location: Cape Canaveral, Florida
Trajectory A: To Pluto using Jupiter's gravity.
Way
Beginning of the journey: The first 13 months - the extraction of the spacecraft and the inclusion of instruments, calibration, minor corrections of the trajectory with the help of maneuvers and a rehearsal of the encounter with Jupiter. New Horizons orbited Mars on April 7, 2006; he also tracked a small asteroid later named "APL" in June 2006.
Jupiter: Closest approach occurred on February 28, 2007 at 51,000 miles per hour (about 23 kilometers per second). New Horizons flew 3 to 4 times closer to Jupiter than the Cassini spacecraft, which is within 1.4 million miles (2.3 million kilometers) due to the planet's large size.
Interplanetary Cruise: During the approximately 8-year journey to Pluto, all spacecraft instruments were turned on and tested, course trajectories were corrected, and an encounter with a distant planet was rehearsed.
During the cruise, New Horizons also traveled to the orbits of Saturn (June 8, 2008), Uranus (March 18, 2011) and Neptune (August 25, 2014).
Pluto system
In January 2015, New Horizons began the first of several landing phases, culminating in the first major flyby of Pluto on July 14, 2015. On its closest approach, the craft will fly within about 7,750 miles (12,500 kilometers) of Pluto and 17,900 miles (28,800 kilometers) of Charon.
Beyond Pluto: The Kuiper Belt
The spacecraft has the ability to fly beyond the Pluto system and explore new Kuiper Belt Objects (KBOs). It carries additional hydrazine fuel for the overflight to the OPK; the spacecraft's communications system is designed to operate even far beyond Pluto's orbit, and scientific instruments can function in conditions worse than those in the dim sunlight on Pluto.
Thus, the New Horizons team had to undertake a special search for small bodies in the KBO system that the ship could reach. In the early 2000s, the Kuiper Belt was not even discovered. The National Academy of Sciences will direct New Horizons to fly to small CMOs 20 to 50 kilometers (about 12 to 30 miles) across, which are likely primitive and less informative than planets like Pluto.
In 2014, using the Hubble Space Telescope, members of the New Horizons science team discovered three objects within the CSO, all 20 to 55 kilometers across. Possible dates for their flyby are late 2018 or 2019 at a distance of a billion miles from Pluto.
In the summer of 2015, after the Pluto flyby, the New Horizons team will work with NASA to select the best candidate among the three. In autumn 2015, operators will start the engines aboard New Horizons at the optimum time to minimize the fuel needed to reach the chosen destination and start the journey.
All NASA missions seek to do more than just reconnaissance of their primary objectives, which is why a request for funding for an extended mission has been sent to them. A proposal to study additional PCR will be put forward in 2016; it will be evaluated by an independent panel of experts to find out the full merits of such a move: the team will analyze the health of the spacecraft and its instruments, the contribution to science that New Horizons can make to the DSO, the cost of flying and researching a target point in the Kuiper Belt, and much more .
If NASA approves such a move, New Horizons will launch a new mission in 2017 and give its team time to plan for an impact one to two years later.
For the first (and only time) in the history of the space age, NASA applied for permission to visit the vicinity of the planet from its discoverer. Permission was given, and now we can observe amazing pictures of a distant world - the former planet Pluto, the most distant from the Sun.
The American astronomer Clyde Tombaugh, who discovered Pluto as a young man in 1930, hardly imagined at that moment that someday people would be able to send a spacecraft to his new discovery. The idea of a mission to the ninth planet arose in the early 1990s, when its discoverer was still alive. As a result, in 1992, 86-year-old Tombo received an unexpected message from the Jet Propulsion Laboratory (JPL) of NASA, asking him for permission to visit Pluto. Of course, this permission did not have any legal status, but it was a very beautiful gesture - a tribute to the person who discovered the farthest frontier of the solar system.
Tombo died in 1997, less than ten years before the launch of a mission to his planet. However, he received what is probably the most prestigious, unusual, and certainly the most distant funeral in human history: about an ounce (31 g) of his ashes were placed in a spacecraft that went to Pluto and beyond. Along with Tombo's ashes, several more symbolic items went to Pluto: a CD with the recorded names of almost half a million people who took part in the "Send Your Name to Pluto" campaign, part of the skin of the first private SpaceShipOne spacecraft, and a 1991 stamp with the slogan "Pluto . Not explored yet."
Anatomy of a Mission
Work on the New Horizons mission really began in 2000 under the leadership of Alan Stern, director of the Space Research Division at the Southwest Research Institute (SwRI). The forerunners of New Horizons were the Pluto 350 and Pluto Kuiper Express projects, the launch of the latter was even originally scheduled for the year 2000, reaching the planet in 2012-2013. But the project was not lucky - in that very year 2000, the budget was cut, since the cost of the flight was estimated at a billion dollars, and as a result, the mission was simply canceled. The new project was implemented in a very short time - from the creation of a scientific and engineering team to the finished device, only five years passed: by the winter of 2005-2006, the probe assembled and covered with thermal insulation was already at Cape Canaveral, ready to launch.
When looking at this spacecraft, one important detail immediately becomes obvious: it does not look like modern satellites in silhouette - it does not have solar panels. This is not surprising, since Pluto has very little sunlight. The farthest planet that a solar-powered spacecraft has been sent to is Jupiter. A triangular platform with a highly directional antenna on one of the planes ends with a strange cylinder protruding from one of the corners. This is an RITEG, a radioisotope thermoelectric generator. In it, electricity is generated directly by converting the decay heat of a radioactive isotope. The same power source is used in the famous Cassini spacecraft, which has been operating in the Saturn system for more than a decade, and in the Curiosity rover.
Inside the RTG are 11 kg of plutonium-238. This is a very convenient isotope for such purposes: during its decay, a lot of heat is released, and this plutonium emits only heavy alpha particles, from which it is quite easy to protect yourself. The main disadvantage of this isotope is its scarcity: it was a by-product in the production of weapons-grade plutonium, and at present this process has been stopped both in the USA and in Russia. Therefore, New Horizons has three times less plutonium (and energy reserves) than, say, Cassini.
Nine and a half years of travel
Russian RD-180 engines, installed on the Atlas V launch vehicle, carried the device from the spaceport at Cape Canaveral. New Horizons became the fastest spacecraft "at launch": after the boosters were turned off, the speed of the probe relative to the Earth was 16.26 km / s, and the speed relative to the Sun - 45 km / s. However, now the device is flying at a speed of 14.5 km / s relative to the Sun, so the title of the fastest spacecraft has returned to the famous Voyager-1, which is moving away from our star at a speed of more than 17 km / s. But even with such speeds, it will take a long time to get to Pluto. Now the signal from the device goes to the Earth for almost five hours.
Along the way, New Horizons set a world record not only for the speed of removal from the Earth, but also for the speed of travel to the Moon: only 8 hours and 35 minutes. A little over a year later, the device made a gravitational maneuver near Jupiter. At this time, all scientific instruments were tested and the amazing Galilean satellites of Jupiter and the largest planet in the solar system were studied. For example, we managed to get the most beautiful pictures of volcanoes on the moon Io. At the beginning of the flight, New Horizons also managed to photograph a small asteroid - to test the image capture systems. The spacecraft managed to take the first picture of Pluto already in the first year of the flight, in September 2006. The picture had no scientific value, but it demonstrated the capabilities of the LORRI camera. But most of the time, two-thirds of the entire flight, the device "slept", or, scientifically, was in hibernation mode - 1837 days, divided into 18 periods from 36 to 202 days long, the device did not get in touch, but simply flew saving energy.
Degraded planet
In the summer of 2006, when the device was already flying towards its target, a landmark event occurred that caused heated debate. The fact is that the next General Assembly of the International Astronomical Union (IAU) decided to finally put things in order in planetary terminology. Indeed, over the past decades, many different objects have been discovered in the Kuiper belt beyond Neptune, and some of them were comparable in size to Pluto, or even larger. Do they also need to be recorded as planets? As a result of intense debate, astronomers decided to change the wording and consider only that body that satisfies the following three conditions as a planet. First, it itself revolves around the Sun. Secondly, it is massive enough to acquire a shape close to spherical under the action of hydrodynamic equilibrium. And thirdly, it is massive enough that the space surrounding it is cleared of other celestial bodies.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune passed the new test from the IAU, and Pluto "cut off" on the third condition. Now it, like Ceres from the asteroid belt, as well as Haumea, Makemake and Eris from the Kuiper belt, is considered a dwarf planet. However, now the movement “Bring Pluto back to the family!” has begun again. The family of classical planets, of course.
22 hours of silence
However, despite the fact that the main target of the mission was struck in rights, the flight continued. Since January 2015, astronomers have been constantly observing the approaching Pluto. In the spring, two important milestones were passed. On March 12, less than one astronomical unit remained to Pluto (1 AU is the distance from the Earth to the Sun), and on May 5, the resolution of images of the Pluto system and its satellites exceeded the maximum value that can be obtained using the Hubble telescope. A little later, photographs and animations were published showing the movement of all five satellites of Pluto - large Charon and very small Nikta, Hydra, Kerberus and Styx. These images confirmed calculations based on observations from the Hubble telescope: due to gravitational disturbances caused by Charon, the remaining satellites (small melon-shaped bodies) tumble in flight and fly in irregular orbits. Every day Pluto and Charon became more and more visible, more and more details could be seen on them. Everyone was waiting for the day of closest approach on July 14, when suddenly...
Ten days before the date of closest approach, July 4, the device's on-board computer failed. Communication with the control center on Earth was interrupted for 81 minutes. In conditions when the signal goes one way for four and a half hours, and you need to wait all nine for an answer, this made the scientists a little worried. Nevertheless, the device's computer systems themselves coped with the failure, and preparations for rendezvous continued.
And then came "X day for planet X" - July 14, 2015, the day that all astronomers have been waiting for more than nine years. The device transmitted to Earth the first detailed image of the surface of Pluto ... and fell silent, this time - for a long 22 hours. But it was a planned silence, for the duration of the main scientific mission, radio communication with the Earth was turned off. The probe flew through the Pluto system at a distance of 12,500 km from its surface, managed to turn the cameras and managed to photograph the dark side of Pluto, seeing the halo of the atmosphere around the dark disk. And then the most interesting began.
Those who witnessed the birth of the Internet in the 1990s remember how long it took to download a short video file using a telephone modem at 16,600 bps to a home computer. So, on Pluto the situation is even worse. The data transfer rate barely reaches 1000 bps.
And during the flight past Pluto, the probe collected about 50 GB of scientific information that needs to be transferred to Earth - this is precisely the purpose of the mission. The transfer of this data will take ... almost two years, until March 2017. Of course, the first images and the most important scientific data were already transmitted in the early days. And now the transmission of new images has been suspended for two whole months.
During the flyby of Pluto, the probe collected about 50 gigabytes of scientific information that needs to be transferred to Earth - this is precisely the purpose of the mission.
Views of Pluto
The main images already taken are high resolution images of Pluto and Charon. The Pluto-Charon system is generally unique - it is the only double planet in the solar system. It is double: Charon is so large that they and Pluto revolve around a common center of mass, which is located behind the surface of Pluto. To make this easier to imagine, imagine a hammer spun hammer. Here, the hammer does not revolve around the athlete, but the two of them “dance” around some point.
Pluto itself has amazed astronomers. First, it turned out to be very similar to Triton: this confirms the conjecture that the largest satellite of Neptune was captured from the Kuiper belt. Secondly, no one expected to see a heart on Pluto. However, the bright region in the first large image of the dwarf planet turned out to be similar to the symbol of the heart. However, the pranksters successfully entered a portrait of the Disney dog Pluto into it.
Plutonian cartography also began. The two largest formations on Pluto were named Tombo in honor of the discoverer of the planet and Sputnik in honor of the first Soviet spacecraft. By the way, Sputnik became the main surprise of Pluto - after a few days it turned out that it was not a plain, but an ice sheet with moving glaciers. The Ralf instrument confirmed large amounts of methane and nitrogen ice on Pluto. The detailed images clearly show how, on the northern border of a flat (without a single crater!) Satellite, the glacier flows into the old crater. Scientists have already noted that Sputnik images resemble satellite images of Antarctica, and this was completely unexpected.
distant worlds
Pluto-Charon is the only double planet in the solar system. The dwarf planet Charon's moon is quite massive, so they orbit a common center of mass, which is outside Pluto's surface. The first large-scale images of Pluto allowed astronomers to conclude that it is similar to Triton (a satellite of Neptune), - this was one of the confirmations that Triton is one of the "natives" of the Kuiper belt. The photographs made it possible to create the first maps of Pluto, the two largest formations were named "Tombo Plain" in honor of the discoverer of the planet and "Sputnik Ice Sheet" in honor of the first Soviet spacecraft. After the flyby, the spacecraft took a picture of a solar eclipse by Pluto (the structure of the aurora can tell about the composition and dynamics of the Plutonian atmosphere). And finally, for the first time, large-scale images of satellites - Charon, as well as much smaller Nikta and Hydra were taken.
The device managed to see the far side of Pluto and take a picture of a solar eclipse in the Kuiper belt. New Horizons was able to photograph how Pluto covers the Sun, and see the glow of the atmosphere around the dwarf planet. Based on the auroral structure, the first conclusions about the composition and dynamics of the Plutonian atmosphere are already being made.
The mountains on Pluto were also very unusual. In height - no less than 3.5 km - these are almost the Ural Mountains, but they are young, small craters are almost not visible in the picture of the mountains. High-resolution photographs of the peaks have already been transmitted to Earth. Perhaps these are not just mountains, but cryovolcanoes.
There is also the first data on satellites - pictures of tiny Nikta (color) and Hydra (black and white) have already been transmitted. A mysterious red spot is visible on Nikta, but what it is is not yet clear. Of course, Charon did not go unnoticed either. One of the first to be transmitted to Earth was his detailed image, which clearly shows numerous craters and traces of Charon's geological activity - faults and young mountains. Presumably, it was also possible to see a growing cryovolcano (however, so far without traces of vital activity). A huge dark spot, which was visible in early images, turned out to be a strange depression, not very similar to the impact basin of a large crater.
distant goals
For the next two years, the task of the apparatus is to transmit the received data and delight the inhabitants with beautiful pictures, and scientists with new riddles. And just fly. The fact is that now New Horizons is a stone thrown into the sky. It has no fuel for a significant course change. The maximum that the crew of the apparatus can afford is to deviate its trajectory by a small angle, up to one degree. But where exactly to reject? By the time the mission was launched, not a single Kuiper belt object was known in that region of outer space. Will it all end with Pluto? After all, the energy of a radioisotope generator will last another ten years. Fortunately, the veteran Hubble telescope has been in space for a long time. Especially for the New Horizons mission, a search was made for suitable candidates in the right sector of the sky. It was possible to find three objects - with different probability of reaching them by the explorer of Pluto.
The object 2014 MU69 (1110113Y) with a diameter of about 60 km seems to be the most successful - New Horizons will reach it with a 100% probability, spending only 35% of the remaining fuel on maneuvers. The second candidate was the asteroid 2014 PN70 (G12000JZ). The probability of successfully reaching it is slightly less - 97%, while almost all of the fuel will be used up, but this goal has its pluses: this object is twice the size of the first, which increases its scientific value. At first, the third discovered Hubble object, asteroid 2014 OS393 (e31007AI), was also considered, but then it became clear that the probability of seeing it was only 7%. He has now been removed from the list of candidates.
The choice of target will be made very soon - as soon as the scientists get a little breather. This means that soon we will again be waiting for photographs of a world that no one has ever seen before.
The New Horizons probe is the first spacecraft ever built to reach Pluto, and the scientific information it gathered along the way will eventually rewrite our textbook on this tiny, icy world we know so little about.
The New Horizons mission is unique in many ways and even has a few secrets on board.
Here are 11 curious facts about the incredible mission to Pluto.
The launch of New Horizons was the fastest in history
On January 19, 2006, NASA attached the New Horizons spacecraft to the top of an Atlas-V rocket and launched into space. It was the fastest launch in history, reaching over 58,000 km/h. Just nine hours after launch, the spacecraft had already reached the moon. It took the Apollo astronauts three days to reach it. The New Horizons probe reached her eight times faster.
When the New Horizons probe was launched, Pluto was still a planet
When the probe was launched, scientists were already whispering anxiously about Pluto's status as a planet. That's because the Pluto-sized object Eris was discovered in 2005, and astronomers had to decide whether Eris would become the tenth planet, or whether it would be easier to revise the definition of a planet.
Ultimately, Pluto ceased to be a planet five months after the launch of New Horizons.
Despite the fact that the New Horizons probe was created for Pluto, he also looked at Jupiter
In 2007, New Horizons made an important encounter with Jupiter. The spacecraft needed the powerful gravity of a giant planet, which accelerated the probe like a shot from a slingshot in the direction of Pluto. This flyby was successful and propelled the probe another 14,500 km/h.
The New Horizons probe made the first video of the eruption of an extraterrestrial volcano
One of Jupiter's moons, Io, serves more than four hundred volcanoes, making it the most geologically active and driest object in our solar system. As the New Horizons probe approached Jupiter, it took a series of images of Io that revealed volcanic bursts on the surface.
Together, these images made it possible to create the first video of an erupting volcano outside the Earth.
New Horizons carries ashes of Pluto discoverer Clyde Tombaugh
Tombo discovered this dwarf planet in 1930, and 67 years later, dying, he asked to send his ashes into space. NASA placed a handful of his ashes on top of New Horizons before it launched in 2006. His remains "visited" the planet he discovered. However, Tombo's ashes are just one of a number of secrets aboard the New Horizons.
New Horizons probe runs on nuclear fuel
The New Horizons probe flies so far from the Sun that it cannot rely on solar panels to generate power. Instead, his nuclear battery converts the radiation from the decay of plutonium atoms into electricity, thus powering his engine and instruments on board so that he gathers as much information as possible.
Such batteries are in short supply. NASA, for example, has plutonium left for a couple of these. And they are not going to produce yet.
There are seven instruments on board the New Horizons, two of which are named after characters from a television series from the 1950s.
Five of the seven New Horizons instruments are represented by acronyms. Some of them sound familiar like PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) and REX (Radio Science Experiment).
Two instruments without acronyms in their names are Ralph and Alice (Ralph and Alice). Ralph will help scientists study the geology and composition of Pluto's surface, while Alice will study Pluto's atmosphere. Ralph and Alice (or Alice) are the two main characters in the 1950s television series Honeymooners.
All New Horizons instruments operate with minimal power consumption, especially the Ralph camera
Although the Ralph camera was built over 10 years ago, it is one of the most ingenious cameras ever made. It weighs about 10 kilograms and requires the same amount of energy to operate as a small table lamp.
This powerful tool can see details of Pluto's surface up to 60 meters across.
A tiny piece of debris could destroy a craft
Now New Horizons is flying through space at a speed of 50,000 km/h. If it gets hit by a piece of ice or dust, the spacecraft will be destroyed before it has a chance to send data back to mission control.
"Even tiny particles the size of a grain of rice can be lethal to New Horizons because we're moving so fast," says Alan Stern, New Horizons principal investigator.
The mission will not end with Pluto
If everything goes well with Pluto, or if New Horizons has enough fuel left, the probe will fly further to study at least one more object in the region of the solar system outside our Kuiper belt planets.
This belt lies at the edge of our solar system and is 20 times wider than the asteroid belt that separates Mars from Jupiter. Astronomers think that it can store the debris of celestial objects left over from the formation of our solar system.
It's been 26 years since we last "first" looked at the planet
The last time this happened was in 1989 when Voyager flew past Neptune. Since then, we have not explored new worlds. The current flyby of Pluto is historic.
