The NASA project Neowise, which gives the astronomers a detailed view of almost earthly objects, some of which were able to beat the earth-their mission and burned back into the atmosphere for over a decade.
In a clear night, the sky is full of bright objects – from stars, large planets and galaxies to tiny asteroids that fly near the earth. These asteroids are generally known as near-earth objects and receive a variety of sizes. Some are tens of kilometers above or larger, others are only ten meters or smaller.
Occasionally, almost earth beat objects at high speed into the earth, 10 miles per second (16 kilometers per second) or faster. This is about 15 times as fast as the muzzle speed of a rifle. An impact on this speed can easily damage the surface of the planet and everything.
The effects of large almost earth -end objects are generally rare in a typical human lifespan. But they are more common in a geological time scale from millions to billions. The best example can be a 6-mile-wide Asteroid (10 kilometers) that fell against the earth, killed dinosaurs and created chicxulub crater about 65 million years ago.
Smaller effects are very common on earth because there are smaller near earth objects. An international community effort called Planetary Defense protects people from these spatial intruders by cataloging and monitoring as many almost earthly objects as possible, including those who are closely approaching the earth. Researchers call the almost earth -end objects that could potentially collide with the surface.
The NEOWISE mission began its operations in 2010 as part of the Landfeld Infrared survey Explorer, Wise, Mission. It examined the near-earth objects such as asteroids and comet even after the expired of their cryogenic coolant to February 2011. After two years of hibernation, the mission reactivated from December 2013 to 2024 and continued to work.
Neowise contributed to planetary defense efforts to catalog his research in order to catalog almost the ground. In the past ten years, planetary defenders like us and our colleagues have helped to study almost earth.
Recognize near-earth objects
Neowise was a groundbreaking mission because it revolutionized how to examine almost earth’s objects.
The NEOWISE mission continued to use the spaceship from the Wise Mission of NASA, which ran from the end of 2009 to 2011 and carried out an all-sky infrared survey in order not only to see near earth objects, but also distant objects such as galaxies.
The spaceship circled the earth from north to the south, over the poles and was in a solar synchronous orbit, where it could see the sun in the same direction over time. This position made it possible to efficiently scan the entire sky.
The spaceship could examine astronomical and planetary objects by recognizing the signatures they have emitted in the middle infrared area.
Man’s eyes can feel visible light, which is an electromagnetic radiation between 400 and 700 nanometers. When we look at stars in the sky with the naked eye, we see their visible light components.
However, the middle infrared light contains waves between 3 and 30 micrometers and is invisible to human eyes.
When heating, an object stores this thermal energy. Unless the object is thermally insulated, this energy in the middle infrared range is continuously released as electromagnetic energy.
This process, which is known as the thermal emission, comes close to the earth after warming up of the sun. The smaller an asteroid, the weaker its thermal emission. The Neowise spaceship was able to record the thermal emissions of almost earth-end objects at a high level of sensitivity. It could recognize small asteroids.
But asteroids are not the only objects that emit heat. The sensors of the spacecraft could also absorb heat emissions from other sources – including the spaceship itself.
In order to ensure that the heat from the spaceship did not hinder the search, the wise/Neowise spaceship was designed in such a way that it could actively cool off with the then state, solid cryogenic hydrogen cooling systems.
Operating phases
Since the devices of the spacecraft had to be very sensitive in order to recognize far away objects by wise, it used solid hydrogen that is extremely cold to cool off and avoid all noise that could mess with the sensitivity of the instruments. After all, the coolant went out, but not as Wise had successfully completed his scientific goals.
During the cryogenic phase, in which it was actively cooled, the spacecraft worked slightly higher than the temperature of the universe with a temperature of about -447 degrees Fahrenheit (-266 degrees Celsius), which is about -454 degrees (-270 degrees Celsius). .
The cryogenic phase lasted from 2009 to 2011 for the spaceship to hibernate in 2011.
After the hibernation time, the NASA decided to reactivate the wise spaceship under the mission of Neowise, whereby a more special focus on the detection of objects near earth, which was still feasible even without cooling, was still feasible.
During this reactivation phase, the detectors had to be neither so sensitive, nor did the spaceship last as cold as during the cryogenic cooling phase, since almost earthy objects are closer than the distant goals of Wise.
The result of the active cooling was that two from the four on board long -wave tectors became so hot that they could no longer work, which restricted the vehicle’s ability.
Nevertheless, Neowise used his two operational detectors to continuously monitor almost earlier objects in detail both before and by newly recorded.
Neowises legacy
From February 2024, Neowise had carried out more than 1.5 million infrared measurements of around 44,000 different objects in the solar system. This included around 1,600 discoveries of almost earth -end objects. Neowise also provided detailed size estimates for more than 1,800 near-earth objects.
Despite the contributions of the mission to science and planet defense, it was shut down in August 2024. The spaceship finally fell towards the surface of the earth until the earth’s atmosphere went back and burned on November 1, 2024.
Neowise’s contributions to hunting almost earth gave scientists much deeper insights into the asteroids around the earth. There were also a better idea of what challenges they had to deal with in order to recognize weak objects.
So, has Neowise found all the almost earth’s objects? The answer is no. Most scientists still believe that there are far more objects out there that still have to be identified, especially smaller ones.
In order to continue the legacy of Neowise, NASA is planning a mission called Neo Surveyor. Neo Surveyor will be a next generation space telescope that can examine small asteroids nearby in order to contribute mainly to NASA’s planetary defense efforts. Hundreds of thousands are identified by almost earth objects that are only about 33 feet (10 meters). The start of the spacecraft is planned for 2027.
This article was updated on February 7, 2024 to clarify the early year of the Neowise mission.
This article will be released from the conversation, a non -profit, independent news organization that brings you facts and trustworthy analyzes to help you understand our complex world. It was written by: Toshi Hirabayashi, Georgia Institute of Technology and Yaeji Kim, University of Maryland
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Toshi Hirabayashi is part of several planetary mission teams with NASA, ESA and Jaxa about the Georgia Institute of Technology.
Yaeji Kim does not work for a company or an organization that benefits from this article and have not published any relevant affiliations about their academic appointment.