February 29, 2024

How the Sun Affects Asteroids in Our Solar System

Artists principle of Lucy Mission. Credit: SwRI
Asteroids embody the story of our solar systems start. Jupiters Trojan asteroids, which orbit the Sun on the same course as the gas giant, are no exception. The Trojans are believed to be left over from the objects that eventually formed our worlds, and studying them might use ideas about how the planetary system came to be.
Over the next 12 years, NASAs Lucy objective will check out eight asteroids– consisting of 7 Trojans– to help answer big questions about world formation and the origins of our planetary system. It will take the spacecraft about 3 and a half years to reach its first location. What might Lucy discover?
Like all the planets, asteroids exist in the heliosphere, the huge bubble of space defined by the reaches of our Suns wind. Directly and indirectly, the Sun impacts many elements of existence within this pocket of deep space. Here are a few of the ways the Sun influences asteroids like the Trojans in our solar system.

Like all the planets, asteroids exist in the heliosphere, the large bubble of space defined by the reaches of our Suns wind. Here are a few of the ways the Sun influences asteroids like the Trojans in our solar system.

In the case of the Trojan asteroids that Lucy will visit, their extremely place in space is determined in part by the Suns gravity. These are places where the gravitational forces of two huge items– in this case the Sun and Jupiter– are balanced in such a way that smaller sized things like asteroids or satellites remain put relative to the bigger bodies. The absence of environment has another ramification for asteroid weathering: Asteroids are battered by the solar wind, a steady stream of particles, magnetic fields, and radiation that streams from the Sun.

Location in Space
In the case of the Trojan asteroids that Lucy will check out, their extremely location in area is dictated in part by the Suns gravity. These are locations where the gravitational forces of two massive objects– in this case the Sun and Jupiter– are stabilized in such a way that smaller sized objects like satellites or asteroids stay put relative to the larger bodies.
This video features Lucy Principal Investigator Hal Levison, who goes over the Trojan Asteroids situated at Lagrange Points and how the Lucy mission will outline its trajectory out to visit them. Credits: NASAs Goddard Space Flight Center/James Tralie
Pushing Asteroids Around (with Light!).
Like Earth and lots of other things in space, asteroids rotate. Over millions of years, this force, called the Yarkovsky result, can noticeably modify the trajectory of smaller sized asteroids (those less than 25 miles, or about 40 kilometers, in size).
Sunlight can also modify the rotation rate of little asteroids. This impact, understood as YORP (named for 4 scientists whose work contributed to the discovery), impacts asteroids in various methods depending on their size, shape, and other characteristics.
The Trojans are farther from the Sun than the near-Earth or Main Belt asteroids weve studied before, and it stays to be seen how the Yarkovsky effect and YORP affect them.
Over millions of years, the Yarkovsky impact can visibly modify the trajectory of smaller asteroids. Credit: NASAs Goddard Space Flight Center.
Shaping the Surface.
Just like rocks on Earth show indications of weathering, so too do rocks in space, consisting of asteroids. The phenomenon is more intense on objects without atmospheres, such as asteroids, where temperatures differ hugely. Even though the Trojans are further from the Sun than rocks on Earth, theyll likely reveal more indications of thermal fracturing.
An animation shows numerous particles of solar wind flying from the Sun toward Earth.Asteroids are battered by the solar wind, a consistent stream of particles, electromagnetic fields, and radiation that streams from the Sun. Credit: NASAs Goddard Space Flight.
The lack of atmosphere has another implication for asteroid weathering: Asteroids are battered by the solar wind, a stable stream of particles, electromagnetic fields, and radiation that streams from the Sun. For the a lot of part, Earths electromagnetic field safeguards us from this barrage. Particles that do get through can thrill molecules in Earths atmosphere, leading to auroras. Without electromagnetic fields or environments of their own, asteroids get the impact of the solar wind. When inbound particles strike an asteroid, they can kick some product off into area, changing the basic chemistry of whats left behind.