NASA gears up to deflect asteroid, in key test of planetary defense
THIS SHOULD BE THE JOB OF THEU$A SPACE FORCE INC.
Issam AHMED
Thu, September 22, 2022
Bet the dinosaurs wish they'd thought of this.
NASA on Monday will attempt a feat humanity has never before accomplished: deliberately smacking a spacecraft into an asteroid to slightly deflect its orbit, in a key test of our ability to stop cosmic objects from devastating life on Earth.
The Double Asteroid Redirection Test (DART) spaceship launched from California last November and is fast approaching its target, which it will strike at roughly 14,000 miles per hour (23,000 kph).
To be sure, neither the asteroid moonlet Dimorphos, nor the big brother it orbits, called Didymos, pose any threat as the pair loop the Sun, passing some seven million miles from Earth at nearest approach.
But the experiment is one NASA has deemed important to carry out before an actual need is discovered.
"This is an exciting time, not only for the agency, but in space history and in the history of humankind quite frankly," Lindley Johnson, a planetary defense officer for NASA told reporters in a briefing Thursday.
If all goes to plan, impact between the car-sized spacecraft, and the 530-foot (160 meters, or two Statues of Liberty) asteroid should take place at 7:14pm Eastern Time (2314 GMT), and can be followed on a NASA livestream.
By striking Dimorphos head on, NASA hopes to push it into a smaller orbit, shaving ten minutes off the time it takes to encircle Didymos, which is currently 11 hours and 55 minutes -- a change that will be detected by ground telescopes in the days that follow.
The proof-of-concept experiment will make a reality what has before only been attempted in science fiction -- notably films such as "Armageddon" and "Don't Look Up."
- Technically challenging -
As the craft propels itself through space, flying autonomously for the mission's final phase like a self-guided missile, its main camera system, called DRACO, will start to beam down the very first pictures of Dimorphos.
"It's going to start off as a little point of light and then eventually it's going to zoom and fill the whole entire field of view," said Nancy Chabot of Johns Hopkins Applied Physics Laboratory (APL), which hosts mission control in a recent briefing.
"These images will continue until they don't," added the planetary scientist.
Minutes later, a toaster-sized satellite called LICIACube, which separated from DART a couple of weeks earlier, will make a close pass of the site to capture images of the collision and the ejecta -- the pulverized rock thrown off by impact.
LICIACube's picture will be sent back in the weeks and months that follow.
Also watching the event: an array of telescopes, both on Earth and in space -- including the recently operational James Webb -- which might be able to see a brightening cloud of dust.
Finally, a full picture of what the system looks like will be revealed when a European Space Agency mission four years down the line called Hera arrives to survey Dimorphos's surface and measure its mass, which scientists can only guess at currently.
- Being prepared -
Very few of the billions of asteroids and comets in our solar system are considered potentially hazardous to our planet, and none in the next hundred or so years.
But "I guarantee to you that if you wait long enough, there will be an object," said Thomas Zurbuchen, NASA's chief scientist.
We know that from the geological record -- for example, the six-mile wide Chicxulub asteroid struck Earth 66 million years ago, plunging the world into a long winter that led to the mass extinction of the dinosaurs along with 75 percent of species.
An asteroid the size of Dimorphos, by contrast, would only cause a regional impact, such as devastating a city, albeit with a greater force than any nuclear bomb in history.
Scientists are also hoping to glean valuable new information that can inform them about the nature of asteroids more generally.
How much momentum DART imparts on Dimorphos will depend on whether the asteroid is solid rock, or more like a "rubbish pile" of boulders bound by mutual gravity, a property that's not yet known.
We also don't know its actual shape: whether it's more like a dog bone or a donut, but NASA engineers are confident DART's SmartNav guidance system will hit its target.
If it misses, NASA will have another shot in two years' time, with the spaceship containing just enough fuel for another pass.
But if it succeeds, then it's a first step towards a world capable of defending itself from a future existential threat, said Chabot.
ia/mdl
Issam AHMED
Thu, September 22, 2022
Bet the dinosaurs wish they'd thought of this.
NASA on Monday will attempt a feat humanity has never before accomplished: deliberately smacking a spacecraft into an asteroid to slightly deflect its orbit, in a key test of our ability to stop cosmic objects from devastating life on Earth.
The Double Asteroid Redirection Test (DART) spaceship launched from California last November and is fast approaching its target, which it will strike at roughly 14,000 miles per hour (23,000 kph).
To be sure, neither the asteroid moonlet Dimorphos, nor the big brother it orbits, called Didymos, pose any threat as the pair loop the Sun, passing some seven million miles from Earth at nearest approach.
But the experiment is one NASA has deemed important to carry out before an actual need is discovered.
"This is an exciting time, not only for the agency, but in space history and in the history of humankind quite frankly," Lindley Johnson, a planetary defense officer for NASA told reporters in a briefing Thursday.
If all goes to plan, impact between the car-sized spacecraft, and the 530-foot (160 meters, or two Statues of Liberty) asteroid should take place at 7:14pm Eastern Time (2314 GMT), and can be followed on a NASA livestream.
By striking Dimorphos head on, NASA hopes to push it into a smaller orbit, shaving ten minutes off the time it takes to encircle Didymos, which is currently 11 hours and 55 minutes -- a change that will be detected by ground telescopes in the days that follow.
The proof-of-concept experiment will make a reality what has before only been attempted in science fiction -- notably films such as "Armageddon" and "Don't Look Up."
- Technically challenging -
As the craft propels itself through space, flying autonomously for the mission's final phase like a self-guided missile, its main camera system, called DRACO, will start to beam down the very first pictures of Dimorphos.
"It's going to start off as a little point of light and then eventually it's going to zoom and fill the whole entire field of view," said Nancy Chabot of Johns Hopkins Applied Physics Laboratory (APL), which hosts mission control in a recent briefing.
"These images will continue until they don't," added the planetary scientist.
Minutes later, a toaster-sized satellite called LICIACube, which separated from DART a couple of weeks earlier, will make a close pass of the site to capture images of the collision and the ejecta -- the pulverized rock thrown off by impact.
LICIACube's picture will be sent back in the weeks and months that follow.
Also watching the event: an array of telescopes, both on Earth and in space -- including the recently operational James Webb -- which might be able to see a brightening cloud of dust.
Finally, a full picture of what the system looks like will be revealed when a European Space Agency mission four years down the line called Hera arrives to survey Dimorphos's surface and measure its mass, which scientists can only guess at currently.
- Being prepared -
Very few of the billions of asteroids and comets in our solar system are considered potentially hazardous to our planet, and none in the next hundred or so years.
But "I guarantee to you that if you wait long enough, there will be an object," said Thomas Zurbuchen, NASA's chief scientist.
We know that from the geological record -- for example, the six-mile wide Chicxulub asteroid struck Earth 66 million years ago, plunging the world into a long winter that led to the mass extinction of the dinosaurs along with 75 percent of species.
An asteroid the size of Dimorphos, by contrast, would only cause a regional impact, such as devastating a city, albeit with a greater force than any nuclear bomb in history.
Scientists are also hoping to glean valuable new information that can inform them about the nature of asteroids more generally.
How much momentum DART imparts on Dimorphos will depend on whether the asteroid is solid rock, or more like a "rubbish pile" of boulders bound by mutual gravity, a property that's not yet known.
We also don't know its actual shape: whether it's more like a dog bone or a donut, but NASA engineers are confident DART's SmartNav guidance system will hit its target.
If it misses, NASA will have another shot in two years' time, with the spaceship containing just enough fuel for another pass.
But if it succeeds, then it's a first step towards a world capable of defending itself from a future existential threat, said Chabot.
ia/mdl
After asteroid collision, Europe's Hera will probe 'crime scene'
A NASA mission to deliberately smash a spacecraft into an asteroid blasts off on Monday
September 23, 2022 - AFP
After NASA deliberately smashes a car-sized spacecraft into an asteroid next week, it will be up to the European Space Agency's Hera mission to investigate the "crime scene" and uncover the secrets of these potentially devastating space rocks.
NASA's Double Asteroid Redirection Test (DART) aims to collide with the asteroid moonlet Dimorphos on Monday night, hoping to slightly alter its trajectory -- the first time such an operation has been attempted.
Astronomers around the world will watch DART's impact, and its effect will be closely followed to see if the mission passed the test.
The Hera spacecraft is planned to launch in October 2024, aiming to arrive at Dimorphos in 2026 to measure the exact impact DART had on the asteroid.
- 'A new world' -
Hera will be loaded up with cameras, spectrometers, radars and even toaster-sized nano-satellites to measure the asteroid's shape, mass, chemical composition and more.
"If an asteroid is made up of, for example, loose gravel, approaches to disrupt it may be different than if it was metal or some other kind of rock," she told the International Astronautical Congress in Paris this week.
"Asteroids are not boring space rocks -- they are super exciting because they have a great diversity" in size, shape and composition, Michel said.
"Unless you touch the surface, you cannot know the mechanical response," he said.
For example, when a Japanese probe dropped a small explosive near the surface of the Ryugu asteroid in 2019, it was expected to make a crater of two or three metres. Instead, it blasted a 50-metre hole.
"The surface behaved almost like a fluid," rather than solid rock, he added. "How weird is that?"
Binary systems like Dimorphos and Didymos represent around 15 percent of known asteroids, but have not yet been explored.
Learning about the impact of DART is not only important for planetary defence, Michel said, but also for understanding the history of our Solar System, where most cosmic bodies were formed through collisions and are now riddled with craters.
juc/dl/kjm
A NASA mission to deliberately smash a spacecraft into an asteroid blasts off on Monday
September 23, 2022 - AFP
After NASA deliberately smashes a car-sized spacecraft into an asteroid next week, it will be up to the European Space Agency's Hera mission to investigate the "crime scene" and uncover the secrets of these potentially devastating space rocks.
NASA's Double Asteroid Redirection Test (DART) aims to collide with the asteroid moonlet Dimorphos on Monday night, hoping to slightly alter its trajectory -- the first time such an operation has been attempted.
Astronomers around the world will watch DART's impact, and its effect will be closely followed to see if the mission passed the test.
The Hera spacecraft is planned to launch in October 2024, aiming to arrive at Dimorphos in 2026 to measure the exact impact DART had on the asteroid.
- 'A new world' -
Hera will be loaded up with cameras, spectrometers, radars and even toaster-sized nano-satellites to measure the asteroid's shape, mass, chemical composition and more.
"If an asteroid is made up of, for example, loose gravel, approaches to disrupt it may be different than if it was metal or some other kind of rock," she told the International Astronautical Congress in Paris this week.
"Asteroids are not boring space rocks -- they are super exciting because they have a great diversity" in size, shape and composition, Michel said.
"Unless you touch the surface, you cannot know the mechanical response," he said.
For example, when a Japanese probe dropped a small explosive near the surface of the Ryugu asteroid in 2019, it was expected to make a crater of two or three metres. Instead, it blasted a 50-metre hole.
"The surface behaved almost like a fluid," rather than solid rock, he added. "How weird is that?"
Binary systems like Dimorphos and Didymos represent around 15 percent of known asteroids, but have not yet been explored.
Learning about the impact of DART is not only important for planetary defence, Michel said, but also for understanding the history of our Solar System, where most cosmic bodies were formed through collisions and are now riddled with craters.
juc/dl/kjm
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