The strange orbits of some objects in the farthest reaches of our solar system, hypothesized by some astronomers to be shaped by an unknown ninth planet, can instead be explained by the combined gravitational force of small objects orbiting the sun beyond Neptune, say researchers.
In its last days, the Cassini spacecraft looped between Saturn and its rings so that Earth-based radio telescopes could track the gravitational tug of each. Scientists in Italy and the U.S. have now used these measurements to determine the mass of the rings and estimate its age, which is young: 10-100 million years. This supports the hypothesis that the rings are rubble from a comet or Kuiper Belt object captured late in Saturn's history.
A team of scientists has determined the number of asteroid impacts on the moon and Earth increased by two to three times starting around 290 million years ago. Previous theories held that there were fewer craters on both objects dating back to before that time because they had disappeared due to erosion. The new findings claim that there were simply fewer asteroid impacts during that earlier period.
Using images and thermal data collected by NASA's Lunar Reconnaissance Orbiter (LRO), Southwest Research Institute scientists and their collaborators have calculated the ages of large lunar craters across the moon to be less than 1 billion years. By comparing the impact history of the moon with Earth's craters over this interval, they discovered that the rate of sizable asteroid collisions has increased by a factor of two to three on both bodies over the last 290 million years.
The number of asteroids colliding with the Earth and moon has increased by up to three times over the past 290 million years, according to a major new study involving the University of Southampton. These findings, published in Science challenge our previous understanding of Earth's history.
On the night of Jan. 9, 2019, the V. M. Blanco 4-meter telescope at the National Science Foundation's (NSF) Cerro Tololo Inter-American Observatory (CTIO), high in the mountains of Chile, will close the camera's shutter on the final image from the Dark Energy Survey (DES) -- a survey that has mapped 5,000 square degrees of the heavens, almost one-quarter of the southern sky.
The Juno spacecraft captured new images of a volcanic plume on Jupiter's moon Io during a Dec. 21 flyby. JunoCam, the Stellar Reference Unit (SRU), the Jovian Infrared Auroral Mapper (JIRAM), and the Ultraviolet Imaging Spectrograph (UVS) observed Io for over an hour, providing a glimpse of the moon's polar regions as well as evidence of an active eruption.
As the brilliant comet 46P/Wirtanen streaked across the sky, NASA telescopes caught it on camera from multiple angles.
Using the infrared satellite AKARI, a Japanese research team has detected the existence of water in the form of hydrated minerals in a number of asteroids for the first time. This discovery will contribute to our understanding of the distribution of water in our solar system, the evolution of asteroids, and the origin of water on Earth. The results were published on December 17 in the online Advanced Access edition of Publications of the Astronomical Society of Japan.
A team of astronomers has discovered the most-distant body ever observed in our solar system. It is the first known solar system object that has been detected at a distance that is more than 100 times farther than Earth is from the sun. It was announced Monday by the International Astronomical Union's Minor Planet Center. Carnegie's Scott S. Sheppard, the University of Hawaii's David Tholen, and Northern Arizona University's Chad Trujillo made the discovery.