interstellar objects Archives

September 28, 2021September 29, 2021 by Matt Williams

Vera Rubin Observatory Should Find 5 Interstellar Objects a Year, Many of Which we Could Chase Down With Spacecraft

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

In a year (perhaps two), the Vera C. Rubin Observatory in Chile will become operational and commence its 10-year Legacy Survey of Space and Time (LSST). Using its 8.4-meter (27 foot) mirror and 3.2 gigapixel camera, this observatory is expected to collect 500 petabytes of images and data. It will also address some of the most pressing questions about the structure and evolution of the Universe and everything in it.

One of the highly-anticipated aspects of the LSST is how it will allow astronomers to locate and track interstellar objects (ISOs), which have become of particular interest since `Oumuamua flew through our system in 2017. According to a recent study by a team from the University of Chicago and the Harvard-Smithsonian Center for Astrophysics (CfA), the Rubin Observatory will detect around 50 objects during its 10-year mission, many of which we will be able to study up-close using rendezvous missions.

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 24, 2021September 24, 2021 by Evan Gough

Galactic Panspermia. How far Could Life Spread Naturally in a Galaxy Like the Milky Way?

A new study expands on the classical theory of panspermia, addressing whether or not life could be distributed on a galactic scale. Credit: NASA

Can life spread throughout a galaxy like the Milky Way without technological intervention? That question is largely unanswered. A new study is taking a swing at that question by using a simulated galaxy that’s similar to the Milky Way. Then they investigated that model to see how organic compounds might move between its star systems.

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 new research article shows that Earth's water is as old as the Solar System, and has been present as the Sun grew and the planets formed. 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.

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 18, 2021March 19, 2021 by Matt Williams

Oumuamua Isn’t an Alien Probe, Because Aliens can Learn Everything They Need About us With Telescopes

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

In the Fall of 2017, the first known interstellar object passed through the Solar System, triggering a revolution in astronomy. Because of the amonolous nature of the object, astronomers from all over the world were at a loss to explain what it was. Neither comet, nor asteroid, nor any other conventional object appeared to fit the bill, leading to all kinds of “exotic” explanations.

A particularly exotic explanation was offered by Harvard Professor Avi Loeb and his former postdoc (Dr. Shmuel Bialy), who hypothesized that ‘Oumuamua could have been an extraterrestrial lightsail. Whereas most rebuttal papers questioned the evidence presented, a new study by astrophysicist and UCLA emeritus professor Ben Zuckerman questioned something else: why would an extraterrestrial civilization want to send a probe our way?

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.

November 19, 2020November 19, 2020 by Matt Williams

Earth and the Moon Might Have Captured an Old Upper Stage Rocket

The crescent Earth rises above the lunar horizon in this spectacular photograph taken by the Apollo 17 crew in lunar orbit in December, 1972, during NASA’s final lunar landing mission in the Apollo program. Credit: NASA. Image editing and enhancement: Kevin Gill.

Back in September, the Pan-STARRS1 survey telescope noticed an object that followed a slight but distinctly curved path in the sky, a telltale sign that it was captured by Earth’s gravity. Initially, this object was thought to be a near-Earth Asteroid (NEA) and was given a standard designation by the Minor Planet Center (2020 SO). However, the Center for Near-Earth Object Studies (CNEOS) at NASA JPL had another theory.

Based on its orbit and the way solar radiation appeared to be pushing it off course, NASA scientists have since concluded that the object might actually be the spent upper stage booster of the Centaur rocket that launched the Surveyor 2 spacecraft towards the Moon in 1966. This finding could have implications for future surveys that pick up mysterious objects near Earth (‘Oumuamua occur).