“Those tiny objects with masses comparable to giant planets may themselves be able to form their own planets,” said Dr. Aleks Scholz.

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What can rogue planets teach us about the formation and evolution of stars and planets? This is what a recent study published in The Astronomical Journal hopes to address as an international team of researchers investigated NGC 1,333, which is a star-forming cluster located just under 1,000 light-years from Earth. This study holds the potential to help scientists better understand the formation and evolution of stars and planets while challenging previous hypotheses about these processes.

“We are probing the very limits of the star forming process,” said Dr. Adam Langeveld, who is an assistant research scientist at Johns Hopkins University and lead author of the study. “If you have an object that looks like a young Jupiter, is it possible that it could have become a star under the right conditions? This is important context for understanding both star and planet formation.”

For the study, the researchers used NASA’s James Webb Space Telescope to observe brown dwarfs that comprise NGC 1,333 in hopes of learning more about how stars form. in the end, the researchers discovered six new rogue planet candidates—officially called free-floating planetary-mass objects (FFPMOs)—with masses ranging between 5–10 Jupiters and that exhibit dusty disks orbiting them. This indicates they are some of the smallest objects formed from processes that are traditionally responsible for creating stars and brown dwarfs, the latter of which never reach appropriate sizes to produce nuclear fusion in their cores.

What did NASA’s Double Asteroid Redirection Test (DART) spacecraft on the asteroid moon, Dimorphos, teach astronomers about altering the trajectory of asteroids and asteroids’ formation and evolution? This is what a recent study published in The Planetary Science Journal hopes to address as an international team of researchers investigated the potential geological changes made to Dimorphos, which orbits its parent asteroid, Didymos, when DART impacted the former in September 2022. This study holds the potential to help scientists better understand the formation and evolution of asteroids throughout, and potentially beyond, the solar system, which could hold implications for the early history of the solar system, as well.

“For the most part, our original pre-impact predictions about how DART would change the way Didymos and its moon move in space were correct,” said Dr. Derek Richardson, who is a professor of astronomy at the University of Maryland, a DART investigation working group lead, and lead author on the study. “But there are some unexpected findings that help provide a better picture of how asteroids and other small bodies form and evolve over time.”

For the study, the researchers analyzed post-impact data of the DART spacecraft on Dimorphos based on predictions made prior to the impact, which could help in planning for the European Space Agency’s upcoming Hera spacecraft mission to Didymos, which is slated to launch in October 2024 and arrive at Didymos in December 2026. In the end, the researchers found that along with Dimorphos’ orbital parameters being influenced by the impact, its physical shape was altered, as well. This resulted in the small asteroid moon becoming elongated towards its poles, whereas its poles were squished prior to impact. This indicates varying formation and evolutionary processes regarding its geologic composition.

The Earth’s rotation has been decelerating throughout its history due to tidal dissipation, but the variation of the rate of this deceleration through time has not been established. We present a detailed analysis of eight geological datasets to constrain the Earth’s rotational history from 650 to 240 Mya. The results allow us to test physical tidal models and point to a staircase pattern in the Earth’s deceleration from 650 to 280 Mya. During this time interval, the Earth–Moon distance increased by approximately 20,000 km and the length of day increased by approximately 2.2 h. Specifically, there are two intervals with high Earth rotation deceleration, 650 to 500 Mya and 350 to 280 Mya, separated by an interval of stalled deceleration from 500 to 350 Mya. The interval with stalled deceleration is attributed mainly to reduced tidal dissipation due to the continent-ocean configuration at the time, not to changes in Earth’s dynamical ellipticity from continental assembly or glaciation. Modeling indicates that, except for the very recent time, tidal dissipation is the main driver for decelerating Earth rotation. One potential implication of our findings is that the Earth’s tidal dissipation, along with Earth’s rotation deceleration, may play a role in the evolving Earth.