interstellar object Archives

November 9, 2023November 9, 2023 by Nancy Atkinson

Some of the Moon's Craters are From Interstellar Impacts. Can We Tell Which?

Far Side of Moon Imaged by MoonKAM. This image of the lunar surface was taken by the MoonKAM system onboard NASA’s Ebb spacecraft on March 15, 2012. Credit: NASA/Caltech-JPL/MIT/SRS

By discovering two interstellar objects (ISOs), we know that asteroids and comets from other star systems pass through the Solar System from time to time. By inference, some of these must have crashed into the Moon, creating impact craters. If we could study the impact sites, we might be able to learn about the star systems that they came from.

A new paper suggests there could be a way to determine which lunar craters came from interstellar object impacts. The authors say that young, small craters with high-melt volume near the Moon’s equator are likely the best candidates for ISO-generated craters on the lunar surface.

November 13, 2021November 16, 2021 by Matt Williams

Not Saying it was Aliens, but ‘Oumuamua Probably Wasn’t a Nitrogen Iceberg…

Artist’s impression of the interstellar object, `Oumuamua, experiencing outgassing as it leaves our Solar System. Credit: ESA/Hubble, NASA, ESO, M. Kornmesser

On October 19^th, 2017, astronomers made the first-ever detection of an interstellar object (ISO) passing through our Solar System. Designated 1I/2017 U1′ Oumuamua, this object confounded astronomers who could not determine if it was an interstellar comet or an asteroid. After four years and many theories (including the controversial “ET solar sail” hypothesis), the astronomical community appeared to land on an explanation that satisfied all the observations.

The “nitrogen iceberg” theory stated that ‘Oumuamua was likely debris from a Pluto-like planet in another solar system. In their latest study, titled “The Mass Budget Necessary to Explain ‘Oumuamua as a Nitrogen Iceberg,” Amir Siraj and Prof. Avi Loeb (who proposed the ET solar sail hypothesis) offered an official counter-argument to this theory. According to their new paper, there is an extreme shortage of exo-Plutos in the galaxy to explain the detection of a nitrogen iceberg.

November 7, 2020November 9, 2020 by Matt Williams

Vera Rubin Should be Able to Detect a Couple of Interstellar Objects a Month

The Vera C. Rubin Observatory is under construction at Cerro Pachon, in Chile. This image shows construction progress in late 2019. The VCO should be able to spot interstellar objects like Oumuamua. Image Credit: Wil O'Mullaine/LSST CC BY-SA 4.0, https://en.wikipedia.org/w/index.php?curid=62504391

The Vera C. Rubin Observatory, formerly the Large Synoptic Survey Telescope (LSST), will commence operations sometime next year. Not wanting to let a perfectly good acronym go to waste, its first campaign will be known as the Legacy Survey of Space and Time (LSST). This ten-year survey will study everything from dark matter and dark energy to the formation of the Milky Way, and small objects in our Solar System.

According to a new study by Amir Siraj and Prof. Abraham Loeb of Harvard University, another benefit of this survey will be the discovery of interstellar objects that regularly enter the Solar Systems. These results, when combined with physical characterizations of the objects, will teach us a great deal about the origin and nature of planetary systems (and could even help us spot an alien probe or two!)

June 5, 2020June 5, 2020 by Evan Gough

Interstellar Oumuamua Was a Dark Hydrogen Iceberg

Artist’s impression of the first interstellar asteroid/comet, "Oumuamua". This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawaii. Credit: ESO/M. Kornmesser

When Canadian astronomer Robert Weryk discovered `Oumuamua passing through our Solar System with the Pan-STARRS telescope, in October 2017, it caused quite a stir. It was the first interstellar object we’d ever seen coming through our neighbourhood. The excitement led to speculation: what could it be?

There was lots of fun conjecture on its origins. Was it an alien spacecraft? A solar sail? Or something more prosaic?

May 8, 2020May 8, 2020 by Evan Gough

A Cool Idea to Catch Up With an Interstellar Visitor

Poor, dim-witted humanity.

We used to think we were the center of everything. That wasn’t that long ago, and even though we’ve made tremendous advancements in our understanding of our situation here in space, we still have huge blind spots.

For one, we’re only now waking up to the reality of interstellar objects passing through our Solar System.

April 16, 2020April 16, 2020 by Evan Gough

Astronomers Finally Think They Understand Where Interstellar Object Oumuamua Came From and How it Formed

‘Oumuamua caused quite a stir when it visited our Solar System in 2017. It didn’t stay long, however, and when it was spotted with the Pan-STARRS telescope in Hawaii on October 19th, it was already leaving. But its appearance in our part of the Universe spawned a lot of conjecture on its nature and its origins.