Improved version https://youtu.be/sHS31YwgRyo
According to the Wikipedia:
101955 Bennu (provisional designation 1999 RQ36) is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999. It is a potentially hazardous object that is listed on the Sentry Risk Table with the second-highest cumulative rating on the Palermo Technical Impact Hazard Scale. It has a cumulative 1-in-1,750 chance of impacting Earth between 2175 and 2199. It is named after the Bennu, the ancient Egyptian mythological bird associated with the Sun, creation, and rebirth.
Dimensions 565 m × 535 m × 508 m
Mean radius 245.03±0.08 m
Equatorial radius 282.37±0.06 m
Polar radius 249.25±0.06 m
Surface area 0.782±0.004 km^2
Volume 0.0615±0.0001 km^3
Mass (7.329±0.009)×1010 kg
Mean density 1.190±0.013 g/cm^3
Equatorial surface gravity 6.27 micro-g
Rotation period ~4.296 h
North pole right ascension +85.65±0.12°
North pole declination −60.17±0.09°
Geometric albedo 0.044±0.002
Surface temp. min mean max
Kelvin 236 259 279
Fahrenheit -34.6 6.8 42.8
Celsius -37 -14 6
OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is a NASA asteroid-study and sample-return mission. The mission's primary goal is to obtain a sample of at least 60 g (2.1 oz) from 101955 Bennu, a carbonaceous near-Earth asteroid, and return the sample to Earth for a detailed analysis. The material returned is expected to enable scientists to learn more about the formation and evolution of the Solar System, its initial stages of planet formation, and the source of organic compounds that led to the formation of life on Earth.
The brief "Touch And Go" TAG event for bringing small amounts of sample material from the Asteroid has happened back in 10/20/2020 and the OSIRIS-REx is on it's way back to Earth to bring the samples for analysis. ETA is 9/24/2023
Mission type Asteroid sample return
Operator NASA / Lockheed Martin
COSPAR ID2016-055A
SATCAT no.41757
Website asteroidmission.org
Mission duration
7 years (planned) 505 days at asteroid
4 years, 11 months, 2 days (elapsed) 982 days at asteroid
Spacecraft Properties
Manufacturer Lockheed Martin
Launch mass 2,110 kg (4,650 lb)
Dry mass 880 kg (1,940 lb) Dimensions 2.44 × 2.44 × 3.15 m (8 ft 0 in × 8 ft 0 in × 10 ft 4 in)
Power 3000 w
Launch date 8 Sept. 2016, 23:05 UTC
Rocket Atlas V 411 (AV-067)
Launch Site Cape Canaveral, SLC-41
Contractor ULA
End of Mission Landing date 24 September 2023, 15:00 UTC (planned)
Landing site Utah Test and Training Range
Source Media Credits:
NASA's Goddard Space Flight Center
NASA's Conceptual Image Lab
University of Arizona
Lockheed Martin
Music from YouTube Audio Library for creators
In 2135, a potentially hazardous asteroid called Bennu will make a close flyby of Earth.
During this encounter, our planet’s gravity will tweak Bennu’s path, making it a challenge to calculate its future trajectory and the odds of a potential impact late in the 22nd century.
Why is this hard to determine? Well, we know how gravity works…but there are still uncertainties in Bennu’s trajectory that will be magnified by the close encounter.
In addition to gravity, asteroids can be pushed around by non-gravitational forces like the Yarkovsky effect. When sunlight strikes a rotating asteroid, the dayside heats up. As the asteroid turns, the night side cools down and releases the heat. This exerts a small thrust on the asteroid, which can change its direction over time. The Yarkovsky effect is challenging to model, but it can make a big difference in determining where asteroids end up. Because we don’t know exactly how the Yarkovsky effect will perturb Bennu’s orbit, we have limited knowledge of where Bennu will be as it approaches Earth in 2135. Scientists thus have to consider a range of possible trajectories, depending on how strongly the Yarkovsky effect is pushing on Bennu. A few of these trajectories line up with regions of space called gravitational keyholes. If Bennu were to pass through a keyhole, Earth’s gravity would bend its path in just the right way to cause an impact on a subsequent orbit, late in the 22nd century. The odds of this actually happening are quite low, but scientists want to know as much as possible. That’s one reason why NASA sent the OSIRIS-REx spacecraft to study Bennu from 2018 to 2021. OSIRIS-REx greatly improved our knowledge of Bennu’s position, density, thermal inertia, and other properties that can influence how its orbit will evolve over time. The new data allowed scientists to significantly reduce uncertainties in Bennu’s predicted orbit, ruling out a number of keyholes for the 2135 flyby, and eliminating several future impact scenarios. While Bennu remains a hazardous asteroid, we can now make better models of its orbital evolution thanks to OSIRIS-REx. This will allow us – and our descendants – to better calculate Bennu’s risk in the decades and centuries to come.
0 Comments