The asteroid "Bennu" could one day become dangerous for Earth.
Therefore, the NASA mission "Osiris-Rex" should help to better calculate the trajectories of asteroids.
The
asteroid "Bennu"
could
one day become dangerous
for
Earth
.
The
NASA space probe "Osiris-Rex" is
researching the
asteroid
at close range and is supposed
to send
soil samples
to Earth.
The
NASA mission
should also help to
better calculate
the
trajectory of asteroids in the
future
.
Asteroid
the coming
Earth
always close again without presenting a danger.
But with some asteroids it is different: They are on a collision course with the earth or could end up on a collision course with a minimal change in their trajectory.
They are therefore on the watch lists of the space agencies, as they have to be monitored regularly.
High up on this list - even higher than the asteroid "Apophis" * - is the
asteroid "Bennu"
.
Asteroid "Bennu" could hit Earth between 2175 and 2199
According to the calculations, there will be
several possible collisions of the asteroid "Bennu" with the earth
between 2175 and 2199
.
And even if the probability of an actual collision is less than 0.07 percent, the
asteroid is
still closely monitored.
For example, it is also possible that a close flight past Earth changes the flight path of the asteroid in such a way that the future
risk of impact
increases.
And "Bennu" is an
asteroid
that is not to be trifled with: it has a diameter of around 490 meters, and calculations show that an impact would cause great damage in the vicinity of the impact site.
However, “Bennu” is not an asteroid whose impact destroys the earth, Dante Lauretta told space.com.
Lauretta is involved in the
NASA space probe "Osiris-Rex"
, which has been
orbiting
the
asteroid "Bennu"
for some time
and whose most important task is imminent.
Nasa space probe "Osiris-Rex" is supposed to bring soil samples from asteroid "Bennu" to earth
The
space probe "Osiris-Rex" set off
for the asteroid "Bennu" in September 2016 in order to examine it closely.
One of her main tasks: to bring samples from the asteroid back to Earth.
"Osiris-Rex" has been orbiting the asteroid since the end of 2018 in order to map its surface in high resolution.
The probe has already set several records:
"Osiris-Rex" orbits the asteroid as closely as no celestial body has been orbited before.
The asteroid "Bennu" is the smallest object in space that has ever been orbited by a probe.
NASA space probe "Osiris-Rex" collects material from asteroid "Bennu"
In the course of time the trajectory of
"Osiris-Rex"
around the asteroid was lowered further and further in order
to be able to map
every square centimeter of
"Bennu"
.
A suitable place was found to take a material sample.
On October 20, 2020, the time has come when the space probe will attempt to
collect
material from the
asteroid
for the first time
.
For this purpose, "Osiris-Rex" will leave its current orbit at an altitude of around 770 meters around the asteroid and slowly descend to the surface of the asteroid.
Once it has reached the selected location called "Nightingale", according to
NASA
, the space probe will
touch the ground for "less than 16 seconds" and emit a gas that is supposed to stir up the surface material from the asteroid, which the space probe can then pick up.
The space probe then fires its engines to move away from the asteroid.
The "reverse vacuum" TAGSAM on @OSIRISREx was invented by our engineer who used a plastic cup, air compressor, and gravel driveway to conduct the first test.
The system will be used to collect a sample from asteroid Bennu.
#ToBennuAndBack
Watch a behind-the-scenes lab test:
- Lockheed Martin (@LockheedMartin) October 6, 2020
NASA probe "Osiris-Rex": return flight from asteroid "Bennu" to Earth in March 2021
"Osiris-Rex"
is supposed to bring at least 60 grams of rock from the
asteroid "Bennu"
back to Earth.
But how do researchers on earth know whether the material collection has been successful?
To check the collection, photos of the “TAGSAM” collection arm should be taken the day after.
In addition, a few days later, a turning maneuver will determine how much material the spacecraft has collected.
If the experts on earth are satisfied with it, the collected material is stowed in a return capsule.
If the collection is unsuccessful, "Osiris-Rex" can make two further attempts at collecting.
It is planned that the space probe's return flight to Earth will begin in March 2021.
In September 2023, "Osiris-Rex" is supposed to launch the capsule with the
asteroid rock
near the earth, shortly afterwards the capsule is to
land
on
earth
, where the valuable cargo is already expected by scientists.
NASA probe "Osiris-Rex" examines Jarkowski effect on asteroid "Bennu"
In addition to collecting the
asteroid samples
that are to be examined in detail on Earth, "Osiris-Rex" has another important task: The
space probe
is to
measure
the so-called
Jarkowski effect
- the influence of the inconsistent
surface heating of asteroids
on their
orbit
and one of the biggest unknowns when it comes to calculating the trajectory of "Bennu" in the future.
In the case of “Bennu”, astronomers have calculated that the
Jarkowski effect
has
shifted the asteroid's trajectory
by 284 meters per year in the direction of the sun since 1999.
The data from "Osiris-Rex" should show how precise this calculation is.
In addition, the data will be used to refine the calculation of the Jarkowski effect in general and to clarify some open questions.
For example, how do mountains or craters on the
asteroid influence
the Jarkowski effect?
"We know that the surface irregularities influence the Jarkowski effect, we have models," explains "Osiris-Rex" team member Steven Chesley.
“But the models are speculative.
So far nobody has been able to test it. "
NASA mission "Osiris-Rex" helps to better calculate the trajectory of asteroids
After the
"Osiris-Rex"
mission,
NASA's
orbit calculations
for the asteroid "Bennu" should be around 60 times better than before, stresses Chesley.
The new findings can also be applied
to other
asteroids
.
In the future, the space organizations
Nasa
and
Esa
want to
jointly
target
an
asteroid
: The
double mission "AIDA"
*
is supposed to
deflect
the small moon of the
asteroid "Didymos"
by the impact of a space probe ("Dart" mission by
NASA
) and then measure the effect ("Hera" mission by
Esa
).
The space agencies want to
try out
a plan for
planetary defense
in practice.
Because so far plans to ward off
dangerous asteroids
only
exist
on paper.
(Tanja Banner)