Asteroids are remnants of the early Solar System, which have the potential to unravel the mysteries of our planet’s origin. But they could also put an end to life on Earth. Now two missions, Lucy And Dart (Double Asteroid Redirection Test) will provide further insight into both of these features – DART is even trying to redirect the Moon’s orbit around an asteroid.
Space rocks are generally considered asteroids if they are larger than about 1 km in size, and are primarily composed of “non-volatile” materials – chemicals that can be easily vaporized. For example, carbon monoxide is unstable because it evaporates at a temperature of -191C. But iron is non-volatile with a vaporization point of 2,862C.
it’s something different comet. Asteroids are more commonly found in the inner Solar System, while comets with their volatile-rich composition lurk in the outer part away from the Sun’s heat. Some 500,000 asteroids have been cataloged to date, and many have small moons of their own.
Asteroids are thought to be the remnants of planets – the precursors of planets in the early Solar System, which coalesced under gravity to form the familiar worlds we know today. The asteroids somehow survived this process, preserving some of the conditions of our early solar system, a time that the planets had formed before. This era is quite mysterious. Tiny particles of dust, which at the time formed a large amount of solid material, were able to collide together and form larger objects such as asteroids, given that they lack significant gravitational fields of their own. , still being Investigated.
The most famous of the asteroids are those that reside in the main belt, a million-strong swarm orbiting the Sun between Mars and Jupiter. It sounds like a lot, but space is huge and the distance between an asteroid and a neighbor is usually millions of kilometers. Thus, the chances of successfully navigating the asteroid field, at least in our solar system, are much better than 3,720 to 1.
The US$980 million (£714 million) Lucy spacecraft – set to launch on 16 October – will while flying Three asteroid fields during its 12-year mission. It is named Lucy after the famous hominin fossil Because it is hoped that it could be equally revolutionary to our knowledge of the origin of the Solar System. Lucy will fly through the main belt first, then travel out to visit two other less familiar asteroid regions – Jupiter Trojan.
Trojan asteroids orbit the Sun at the “Lagrange Points”. These are conditions in space where the gravitational pull of the Sun and a planet is so balanced that an object located there will naturally persist for billions of years. There are five such points for all the planets in the Solar System and they are numbered L1-L5 (see picture below). The Jupiter Trojans, clustered on L4 and L5, are two massive and unexplored asteroid regions that harbor at least as many asteroids as the main belt between them.
Lucy will first venture to the L4 Jupiter Trojan, on which it will arrive in 2027. It will then fly back toward Earth, using our planet’s gravity to propel it back toward the L5 Jupiter Trojan, arriving in 2033. It will be accomplished with remarkable flight path solar-electric propulsion.
The spacecraft carries a suite of instruments, including sophisticated cameras and spectrometers, to map asteroids and understand their composition. It is expected that the chemical composition of Jupiter Trojans will be somewhat different from that of main-belt asteroids, which contain high concentrations of volatile material, blurring the distinction between asteroids and comets. Indeed, recently a Jupiter Trojan contained a . was found comet tail.
Not all asteroids are confined to one belt. Some move throughout the Solar System in orbits that could bring them into close proximity to Earth-like planets. The threat of asteroid impacts is relatively well publicized, especially after Chelyabinsk meteor Which exploded in a Russian city in 2013, injuring more than 1,000 people and causing widespread damage.
Sometime in late November, NASA will attempt to launch DART. This spacecraft will try to intercept 65803 didymos, a near-Earth asteroid with a small moon of its own called Dimorphos. Around 170 meters the Moon will be hit by a 500 kg DART spacecraft with an impact velocity of 6.6 kilometers per second. Its purpose is to observe the change in the orbital momentum of Dimorphos about Didymos as a result of the collision.
This will be accomplished by a follow-up mission launched by the European Space Agency, called Hera, which will reach Didymos in 2026 and conduct a detailed survey of Dimorphos’ orbit. By measuring changes in the small moon’s orbit, scientists and engineers will be able to better calculate how much energy is needed to change the orbit of an asteroid threatening an imaginary future. It should be emphasized that, at present, there are no known future asteroid-Earth collisions, but clearly it is best to prepare for such an event.
There are more asteroid missions in the near future. NASA will launch in August 2022 psyche To visit the asteroid of your name, 16 Manas, which orbits in the main belt. This strange world is more than 200 km long and contains a lot of metal. In fact it is believed to be the open center of a once rising planet in the early Solar System, which suffered a devastating impact at some point in the distant past. The collision ripped apart the fledgling planet’s outer layers, leaving behind an exposed metal-rich core. If this theory turns out to be true, it would be the first time scientists have had the opportunity to directly observe a planet’s core.
It is one of the upcoming missions, and one of several recent the last ones, represent something of a golden age in asteroid research. Asteroids Still Have Many Stories to Tell, Huge economic potential as mined resources, and pose a clear threat to civilization on Earth.
Gareth Dorian is a Post Doctoral Research Fellow in Space Science at the University of Birmingham. This article first appeared on Conversation.
Credit: www.independent.co.uk /