NASA | SOFIA | 2019 Oct 22
A dramatic glimpse of the aftermath of a collision between two exoplanets is giving scientists a view at what can happen when planets crash into each other. A similar event in our own solar system may have formed our Moon.Artist’s concept illustrating a catastrophic collision between two rocky exoplanets
in the planetary system BD +20 307, turning both into dusty debris. Ten years ago,
scientists speculated that the warm dust in this system was a result of a planet-to-
planet collision. Now, SOFIA found even more warm dust, further supporting that two
rocky exoplanets collided. This helps build a more complete picture of our own solar
system’s history. Such a collision could be similar to the type of catastrophic event
that ultimately created our Moon. Credits: NASA/SOFIA/Lynette Cook
Known as BD +20 307, this double-star system is more than 300 light years from Earth with stars that are at least one billion years old. Yet this mature system has shown signs of swirling dusty debris that is not cold, as would be expected around stars of this age. Rather, the debris is warm, reinforcing that it was made relatively recently by the impact of two planet-sized bodies.
A decade ago, observations of this system by ground observatories and NASA’s Spitzer Space Telescope gave the first hints of this collision when the warm debris was first found. Now the Stratospheric Observatory for Infrared Astronomy, SOFIA, revealed the infrared brightness from the debris has increased by more than 10% – a sign that there is now even more warm dust.
... The results further support that an extreme collision between rocky exoplanets may have occurred relatively recently. Collisions like these can change planetary systems. It is believed that a collision between a Mars-sized body and the Earth 4.5 billion years ago created debris that eventually formed the Moon. ...
Planetary Collisions in a Binary Star System
SOFIA Science Center | Universities Science Research Association | 2019 Oct 22
Studying the Evolution of Warm Dust Encircling BD +20 307 Using SOFIA ~ Maggie A. Thompson et al
- Astrophysical Journal 875(1):45 (2019 Apr 10) DOI: 10.3847/1538-4357/ab0d7f
- arXiv.org > astro-ph > arXiv:1903.03041 > 07 Mar 2019