Tuesday, November 23, 2021


 Hey Space Placers!

DART Spacecraft Graphic

Credit: NASA

NASA is set to launch a planetary defense mission called DART - Double Asteroid Redirect Test - tonight from California. The launch is planned for 10:20 p.m. PST (1:20 a.m. EST, Nov. 24) and can be viewed live via NASA TV starting at 9:30 p.m. PST on Tuesday, Nov. 23 (12:30 a.m. EST on Wednesday, Nov. 24).

More information on DART is available here. Take the quiz to become a planetary defender like I did.

The spacecraft will fly to an asteroid named Didymos which has a small moon, arriving in late September 2022. The spacecraft will impact the moon in order to change its orbital characteristics. Didymos DOES NOT AND WILL NOT present a threat to Earth now or after the impact.

Seven million miles from Earth, as described by NASA, "The DART spacecraft will achieve the kinetic impact deflection by deliberately crashing itself into the moonlet at a speed of approximately 6.6 km/s (14,000 mph), with the aid of an onboard camera (named DRACO) and sophisticated autonomous navigation software. The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent, but this will change the orbital period of the moonlet by several minutes - enough to be observed and measured using telescopes on Earth."


Ten days before impact DART will deploy a briefcase sized cubesat made by the Italian Space Agency that will trail DART by about 3 minutes time and provide imagery of the impact via cameras named LUKE and LEIA ( of Star Wars fame). 

As explained by Johns Hopkins Applied Physics Laboratory, which developed and is leading the mission for NASA with an army of partners,  "Not only will DART give Dimorphos a healthy shove at the moment of contact, but the impact’s energy will excavate a crater and blast between 22,000 and 220,000 pounds of asteroid surface material, called ejecta, into space. The recoil “kick” from these ejecta on the asteroid could rival, or even exceed, the direct push from the DART spacecraft. It’s this enhancement in the asteroid’s momentum that makes kinetic impact a particularly attractive deflection technique, and measuring it accurately is a major component of DART’s mission."

The European Space Agency (ESA) will launch in 2024 a spacecraft called Hera to Didymos to study the impact site on the moonlet to get more detailed information. The collected data will help refine our knowledge of asteroids and their moons - about 15% of currently known asteroids - as well as our planetary defenses against them. Hera will arrive at Didymos in 2026.

.Didymos and its moonlet

Fourteen sequential Arecibo radar images of the near-Earth asteroid (65803) Didymos and its moonlet, taken on 23, 24 and 26 November 2003. NASA’s planetary radar capabilities enable scientists to resolve shape, concavities, and possible large boulders on the surfaces of these small worlds. Photometric lightcurve data indicated that Didymos is a binary system, and radar imagery distinctly shows the secondary body.

Credit: NASA

DART is an important mission to our planetary defense against asteroids that are discovered to be an impact threat to our planet. Asteroids as small as 65-feet across pose a significant threat as was proven in the February 15, 2013 Chelyabinsk asteroid detonation  over the city. 1,600 people were injured, a million square meters of glass broken as the result of the equivalent of 600,000 tons of TNT exploding - that is the equivalent of about 35 Hiroshima nuclear warheads. And we never saw it coming as it came out of the Sun.

NASA is also planning on a mission called Near Earth Object Surveyor - NEO Surveyor - which is a space based telescope positioned so that it can find asteroids all around the solar system. 

We are at risk for asteroid impacts - it isn't a matter of if......it is a matter of when as to another, and perhaps even more catastrophic Chelyabinsk event occurs.

Remember, the dinosaurs are dead because they didn't have telescopes and a space program....

Sky Guy in VA

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