2I/Borisov Archives

February 29, 2024February 29, 2024 by Matt Williams

When an Object Like ‘Oumuamua Comes Around Again, We Could be Ready With an Interstellar Object Explorer (IOE)

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 19th, 2017, astronomers with the Pann-STARRS survey observed an Interstellar Object (ISO) passing through our system – 1I/2017 U1 ‘Oumuamua. This was the first time an ISO was detected, confirming that such objects pass through the Solar System regularly, as astronomers predicted decades prior. Just two years later, a second object was detected, the interstellar comet 2I/Borisov. Given ‘Oumuamua’s unusual nature (still a source of controversy) and the information ISOs could reveal about distant star systems, astronomers are keen to get a closer look at future visitors.

For instance, multiple proposals have been made for interceptor spacecraft that could catch up with future ISOs, study them, and even conduct a sample return (like the ESA’s Comet Interceptor). In a new paper by a team from the Southwest Research Institute (SwRI), Alan Stern and his colleagues studied possible concepts and recommended a purpose-built robotic ISO flyby mission called the Interstellar Object Explorer (IOE). They also demonstrate how this mission could be performed on a modest budget with current spaceflight technology.

October 31, 2023November 1, 2023 by Nancy Atkinson

Vera Rubin Observatory Could Find Up to 70 Interstellar Objects a Year

The Vera C. Rubin Observatory is under construction at Cerro Pachon, in Chile. This image shows construction progress in late 2019. The observatory should be able to spot interstellar objects like Oumuamua. Image Credit: Wil O'Mullaine/LSST .

Astronomers have discovered two known interstellar objects (ISO), ‘Oumuamua and 21/Borisov. But there could be thousands of these objects passing through the Solar System at any time. According to a new paper, the upcoming Vera Rubin Telescope will be a fantastic interstellar object hunter, and could possibly find up to 70 objects a year coming from other star systems.

August 3, 2022August 3, 2022 by Scott Alan Johnston

An Interstellar Meteor Struck the Earth in 2014, and now Scientists Want to Search for it at the Bottom of the Ocean

Artist's illustration of a meteorite resting on the floor of the ocean.

Back in 2014, an object crashed into the ocean just off the coast of Papua New Guinea. Data collected at the time indicated that the meteorite just might be an interstellar object, and if that’s true, then it’s only the third such object known (after Oumuamua and Borisov), and the first known to exist on Earth. Launching an undersea expedition to find it would be a long shot, but the scientific payoff could be enormous.

September 27, 2021September 27, 2021 by Evan Gough

What Happens to Interstellar Objects Captured by the Solar System?

An artist’s overview of the mission concept for the Comet Interceptor spacecraft. Credit: ESA

Now that we know that interstellar objects (ISOs) visit our Solar System, scientists are keen to understand them better. How could they be captured? If they’re captured, what happens to them? How many of them might be in our Solar System?

One team of researchers is trying to find answers.

September 15, 2021September 15, 2021 by Evan Gough

Cosmic Rays Erode Away All But the Largest Interstellar Objects

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

So far we know of only two interstellar objects (ISO) to visit our Solar System. They are ‘Oumuamua and 2I/Borisov. There’s a third possible ISO named CNEOS 2014-01-08, and research suggests there should be many more.

But a new research letter shows that cosmic ray erosion limits the lifespan of icy ISOs, and though there may be many more of them, they simply don’t last as long as thought. If it’s true, then ‘Oumuamua was probably substantially larger when it started its journey, wherever that was.

September 9, 2021September 9, 2021 by Evan Gough

Protoplanetary Disks Throw Out More Material Than Gets Turned Into Planets

A protosolar disk is the disk of material around a young stellar object that isn't yet a star. It's called a protoplanetary disk once the star has formed and begun fusion. Planetesimals are the building blocks of planets and are present in both stages of a disk's evolution. Image Credit: NASA/JPL

When a young solar system gets going it’s little more than a young star and a rotating disk of debris. Accepted thinking says that the swirling debris is swept up in planet formation. But a new study says that much of the matter in the disk could face a different fate.

It may not have the honour of becoming part of a nice stable planet, orbiting placidly and reliably around its host star. Instead, it’s simply discarded. It’s ejected out of the young, still-forming solar system to spend its existence as interstellar objects or as rogue planets.

August 26, 2021August 26, 2021 by Brian Koberlein

Interstellar Objects Might Outnumber Solar System Objects in the Oort Cloud

Our solar system is filled with everything from planets to rocky asteroids to small icy bodies beyond Pluto, but surrounding all of it is a diffuse halo of objects known as the Oort cloud. We haven’t directly observed the Oort cloud, but we’re pretty sure it’s there by observing the distribution of comet in our solar system. They can appear from any direction in the sky rather than just along the common plane of known solar system bodies.

April 17, 2021April 17, 2021 by Scott Alan Johnston

When Stars Get Too Close to Each Other, They Cast Out Interstellar Comets and Asteroids

In October 2017, humanity caught its first-ever glimpse of an interstellar object – a visitor from beyond our solar system – passing nearby the Sun. We named it Oumuamua, and its unusual properties fascinated and confounded astronomers. Less than two years later, amateur astronomer Gennady Borisov found a second interstellar object: a comet-like body that began to disintegrate as it passed within 2 AU of the Sun (1 AU equals the distance from Earth to the Sun). Where do these interstellar objects come from? How common are they? With a sample size of just two, it’s difficult to make any generalizations just yet. On the other hand, given what we know about star formation, we can begin to make some inferences about the likely origins of these objects, and what we are likely to see of them in the future.

April 3, 2021April 2, 2021 by Paul M. Sutter

Interstellar Comet Borisov is so Pristine, it’s Probably Never Been Close to a Star Before

This image was taken with the FORS2 instrument on ESO’s Very Large Telescope in late 2019, when comet 2I/Borisov passed near the Sun. Since the comet was travelling at breakneck speed, around 175 000 kilometres per hour, the background stars appeared as streaks of light as the telescope followed the comet’s trajectory. The colours in these streaks give the image some disco flair and are the result of combining observations in different wavelength bands, highlighted by the various colours in this composite image.

By comparing our local Comet Hale-Bopp to the interstellar visitor 2I/Borisov, a team of astronomers have concluded that the interloper is perhaps one of the most pristine comets we’ve ever seen.

March 14, 2021March 14, 2021 by Matt Williams

There Should be About 7 Interstellar Objects Passing Through the Inner Solar System Every Year

A Hubble image of Comet 2IBorisov from October 2019. Image Credit: By NASA, ESA, and D. Jewitt (UCLA) - https://imgsrc.hubblesite.org/hvi/uploads/image_file/image_attachment/31897/STSCI-H-p1953a-f-1106x1106.png, Public Domain, https://commons.wikimedia.org/w/index.php?curid=83146132

In October 19th, 2017, the first interstellar object ever detected flew past Earth on its way out of the Solar System. Less than two years later, a second object was detected, an easily-identified interstellar comet designated as 2I/Borisov. The appearance of these two objects verified earlier theoretical work that concluded that interstellar objects (ISOs) regularly enter our Solar System.

The question of how often this happens has been the subject of considerable research since then. According to a new study led by researchers from the Initiative for Interstellar Studies (i4is), roughly 7 ISOs enter our Solar System every year and follow predictable orbits while they are here. This research could allow us to send a spacecraft to rendezvous with one of these objects in the near future.