New evidence has emerged suggesting that the building blocks of life were delivered to the primordial Earth from space by meteorites, a finding that could help scientists hunt for alien life.
These meteorites would have been the fractured remains of early "unmelted asteroids," a type of planetesimal. Planetesimals are small rocky bodies that served as the main building blocks of the solar system's rocky planets, including Earth.
They were formed around 4.6 billion years ago in the disk of dust and gas around the infant sun as particles around our young star began to stick together, accreting more mass and making progressively larger bodies. READ MORE...
Astronomers may have detected a dozen large objects lurking beyond the Kuiper Belt at the edge of our solar system, suggesting there could be another equally massive, "second Kuiper Belt" hiding beyond the orbit of Pluto.
Researchers may have detected a dozen new, large objects beyond the Kuiper Belt, which suggests that there is lots more stuff in the solar system than we realized. It could even hint that there is a "second Kuiper Belt" further out toward the edge of our stellar neighborhood, Science.org reported.
The sun's influence reaches much further out into space than the eight planets that orbit around it. Beyond Neptune, the solar system stretches out to around 100 astronomical units (AU), which is 100 times the distance between Earth and the sun. For context, the most distant planet from the sun, Neptune, is roughly 30 AU from our home star.
Beyond the edge of the solar system, or heliopause, lies the Oort Cloud — a reservoir of comets and asteroids that are loosely contained by the sun's gravity — that stretches to at least 1,000 AU from the sun, and likely even further.
But a majority of the largest known asteroids, comets and other large objects that lie beyond Neptune's orbit are contained within the Kuiper Belt, which stretches between 30 and 50 AU from the sun.
Famous residents of the Kuiper Belt include the dwarf planet Pluto and the double-lobed object Arrokoth — the most distant object visited by a spacecraft. Planet Nine, if it exists, would also lurk somewhere within the Kuiper Belt.
Until now, very few massive objects in the solar system have been found beyond the Kuiper Belt. READ MORE...
Watch the sun set from a particularly dark patch of Earth and you may spot a triangle of what scientists call zodiacal light extending from where our star passed below the horizon.
Zodiacal light in Earth's skies is created when sunlight bounces off the dust that fills the solar system, the remains of pulverized asteroids and flurry left by passing comets.
And according to new research by a team of astronomers and high school students based in China, a similar phenomenon occurs in the skies of at least a few potentially habitable exoplanets. The light could be one more clue for scientists seeking to puzzle out what those exotic neighborhoods might look like.
"If we can detect zodiacal light from a distant planet system, then this system likely has components like asteroids and comets, which can't be easily detected directly in other ways," lead author Jian Ge, an astronomer at Shanghai Astronomical Observatory in China, said during a news conference held virtually on Jan. 13 by the American Astronomical Society.
