Illustration of NASA’s DART spacecraft and the Italian Space Agency’s (ASI) LICIACube prior to effect at the Didymos double star. Credit: NASA/Johns Hopkins APL/Steve Gribben
Nearly 20 years earlier, a near-Earth asteroid was found to have a moon and the double star was provided the name “Didymos” — Greek for “twin,” a loose description of the bigger primary body and the smaller sized orbiting moon, which ended up being unofficially called Didymos B.
In 2022, that moon will be the target of NASA’s Double Asteroid Redirection Test (DART), the very first full-blown presentation of an asteroid deflection innovation for planetary defense. The DART spacecraft will carry out a kinetic effect, intentionally crashing into the asteroid to alter its movement in area. To mark this historical objective, Didymos B is getting a main name of its own: Dimorphos.
“Upon discovery, asteroids get a temporary name until we know their orbits well enough to know they won’t be lost. Once the Didymos system was identified as the ideal target for the DART mission, we needed to formally distinguish between the main body and the satellite,” stated Andy Rivkin, a research study astronomer and DART examination co-lead at the Johns Hopkins Applied Physics Laboratory (APL), which is developing and handling the objective for NASA.
A Global Effort
Just as protecting our world from possibly harmful asteroids takes an international effort, so does calling an asteroid’s moon.
In 2003, astronomer Petr Pravec, at the Ondřejov Observatory in Czechia, was tracking the brightness of a still-unnamed asteroid when he acknowledged a pattern constant with a little moon. Across the world, planetary researchers Lance Benner, at NASA’s Jet Propulsion Laboratory in Pasadena, California, and Mike Nolan, then at the Arecibo Observatory in Puerto Rico, collected corroborating proof. Together, the findings indicated the presence of a binary asteroid.
The near-Earth asteroid was initially found in 1996 by Joe Montani of the Spacewatch Project at the University of Arizona, however its orbit required to be verified prior to it might be called. Backed by the work of Pravec, Benner, Nolan and other astronomers, Montani recommended “Didymos” to the International Astronomical Union (IAU), which rapidly authorized.
After Didymos B was determined as the target for DART, objective leads at APL motivated the innovators to propose a different name for the system’s moon. Weighing lots of possibilities, they ultimately chose a recommendation by Kleomenis Tsiganis, a planetary researcher at the Aristotle University of Thessaloniki and a member of the DART group. This week, the IAU revealed main approval of the name.
“Dimorphos, which means ‘two forms,’ reflects the status of this object as the first celestial body to have the ‘form’ of its orbit significantly changed by humanity — in this case, by the DART impact,” stated Tsiganis. “As such, it will be the first object to be known to humans by two, very different forms, the one seen by DART before impact and the other seen by the European Space Agency’s (ESA) Hera, a few years later.”
Dimorphos, measuring 160 meters (525 feet) in size, is the best target for the DART test due to the fact that of its orbit around the bigger primary body Didymos (which steps 780 meters, or 0.48 miles, in size), and due to the fact that of the set’s reasonably close distance to Earth in late 2022.
“Astronomers will be able to compare observations from Earth-based telescopes before and after DART’s kinetic impact to determine how much the orbital period of Dimorphos changed,” stated Tom Statler, DART Program Scientist at NASA Headquarters. “That’s the key measurement that will tell us how the asteroid responded to our deflection effort.”
International Collaboration
DART’s effect with Dimorphos will likewise be taped in area by LICIACube, a buddy CubeSat supplied by the Italian Space Agency that will take a trip on, and be released from, DART. Further examination of Didymos and Dimorphos will be carried out by ESA’s Hera objective a couple of years after DART’s effect. The DART and Hera objective groups are interacting through a worldwide cooperation called the Asteroid Impact and Deflection Assessment (AIDA).
“DART is a first step in testing methods for hazardous asteroid deflection,” stated Andrea Riley, DART Program Executive at NASA Headquarters. “Potentially hazardous asteroids are a global concern, and we are excited to be working with our Italian and European colleagues to collect the most accurate data possible from this kinetic impact deflection demonstration.”
DART is the very first objective established for NASA’s Planetary Defense Coordination Office, and one piece of NASA’s larger planetary defense preparation. In 2016, NASA developed the Planetary Defense Coordination Office (PDCO) to lead United States Government efforts to discover and alert of possibly harmful asteroids and comets and to study methods to reduce the danger when possible.
From Didymos B to Dimorphos, it’s a fitting name for an asteroid that will serve double functions as a both a test target and a part of a plan for securing the world in the future.
