Mars Once had Enough Water for a Planet-Wide Ocean 300 Meters Deep

This artist’s impression shows how Mars may have looked about four billion years ago. The young planet Mars would have had enough water to cover its entire surface in a liquid layer about 140 metres deep, but it is more likely that the liquid would have pooled to form an ocean occupying almost half of Mars’s northern hemisphere, and in some regions reaching depths greater than 1.6 kilometres. Credit: ESO/M. Kornmesser

Today, Mars is colloquially known as the “Red Planet” on a count of how its dry, dusty landscape is rich in iron oxide (aka. “rust”). In addition, the atmosphere is extremely thin and cold, and no water can exist on the surface in any form other than ice. But as the Martian landscape and other lines of evidence attest, Mars was once a very different place, with a warmer, denser atmosphere and flowing water on its surface. For years, scientists have attempted to determine how long natural bodies existed on Mars and whether or not they were intermittent or persistent.

Another important question is how much water Mars once had and whether or not this was enough to support life. According to a new study by an international team of planetary scientists, Mars may have had enough water 4.5 billion years ago to cover it in a global ocean up to 300 meters (almost 1,000 feet) deep. Along with organic molecules and other elements distributed throughout the Solar System by asteroids and comets at this time, they argue, these conditions indicate that Mars may have been the first planet in the Solar System to support life.

Continue reading “Mars Once had Enough Water for a Planet-Wide Ocean 300 Meters Deep”

What Would Asteroid Mining do to the World's Economy?

Artist's impression of an astronaut conducting an EVA with an asteroid. Credit: NASA

About a decade ago, the prospect of “asteroid mining” saw a massive surge in interest. This was due largely to the rise of the commercial space sector and the belief that harvesting resources from space would soon become a reality. What had been the stuff of science fiction and futurist predictions was now being talked about seriously in the business sector, with many claiming that the future of resource exploitation and manufacturing lay in space. Since then, there’s been a bit of a cooling off as these hopes failed to materialize in the expected timeframe.

Nevertheless, there is little doubt that a human presence in space will entail harvesting resources from Near Earth Asteroids (NEAs) and beyond. In a recent paper, a team of researchers from the University of Nottingham in Ningbo, China, examined the potential impact of asteroid mining on the global economy. Based on their detailed assessment that includes market forces, environmental impact, asteroid and mineral type, and the scale of mining, they show how asteroid mining can be done in a way that is consistent with the Outer Space Treaty (i.e., for the benefit of all humanity).

Continue reading “What Would Asteroid Mining do to the World's Economy?”

It’ll be Tough to Stop an Asteroid at the Last Minute, but not Impossible

Artist's impression of the DART mission impacting the moonlet Dimorphos. Credit: ESA

On September 26th, 2022, NASA’s Double-Asteroid Redirect Test (DART) made history when it rendezvoused with the asteroid Didymos and impacted with its moonlet, Dimorphos. The purpose was to test the “Kinetic Impact” method, a means of defense against potentially-hazardous asteroids (PHAs) where a spacecraft collides with them to alter their trajectory. Based on follow-up observations, the test succeeded since DART managed to shorten Dimorphos’ orbit by 22 minutes. The impact also caused the moonlet to grow a visible tail!

However, as Hollywood loves to remind us, there are scenarios where a planet-killing asteroid gets very close to Earth before we could do anything to stop it. And there is no shortage of Near Earth Asteroids (NEAs) that could become potential threats someday. Hence why space agencies worldwide make it a habit of monitoring them and how close they pass to Earth. According to a new study by a group of satellite experts, it would be possible to build a rapid-response kinetic impactor mission that could rendezvous and deflect a PHA shortly before it collided with Earth.

Continue reading “It’ll be Tough to Stop an Asteroid at the Last Minute, but not Impossible”

Three New Potentially Hazardous Asteroids Discovered, Including a big one That Measures 1.5 km Across

Recently, Astronomers spotted three near-Earth asteroids (NEAs) hiding in the glare of the Sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years. Could we use space lasers to protect Earth from these hazards? Image Credit: DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA/J. da Silva/Spaceengine

An asteroid 1.5 km across is no joke. Even a much smaller one, about the size of a house, can explode with more power than the first nuclear weapons. When an asteroid is greater than 1 km in diameter, astronomers call them “planet-killers.” The impact energy released from a planet-killer striking Earth would be devastating, so knowing where these asteroids are and where they’re headed is critically important.

Our defensive capability against asteroid strikes is in its infancy, so advance notice of asteroids that could cross Earth’s orbit is critical. We’ll need time to prepare.

Continue reading “Three New Potentially Hazardous Asteroids Discovered, Including a big one That Measures 1.5 km Across”

When an Asteroid Gets Close to Earth, we get a Rare Opportunity to Learn What it’s Made of

Gravity calculations can provide plenty of insight into a variety of phenomena. Everything from Einstein rings to the rocket equation is at least partially dependent on gravity. Now an undergraduate student and professor team from MIT think they have a new use for gravity calculations – understanding the interior density of asteroids.

Continue reading “When an Asteroid Gets Close to Earth, we get a Rare Opportunity to Learn What it’s Made of”

Lucy Took This Picture of Earth as it was Making its Gravity Assist Maneuver

NASA’s Lucy spacecraft captured this image of the Earth on Oct 15, 2022 during the spacecraft's flyby of our planet for a gravitational assist on its way to explore the Jupiter Trojan asteroids. Credits: NASA/Goddard/SwRI

We may take it for granted, but every day we receive picture postcards from the robotic travelers we have sent out to explore our Solar System. Usually, we get to see faraway planets, moons, asteroids, or comets. But sometimes we get to see ourselves.

The Lucy spacecraft took a couple of amazing images of our home planet as the spacecraft was approaching Earth for the first of three slingshot gravity assists on its way out to explore the Trojan asteroids along Jupiter’s orbit.

Continue reading “Lucy Took This Picture of Earth as it was Making its Gravity Assist Maneuver”

The Asteroid That Killed the Dinosaurs Also Flooded the World's Coastlines With a Catastrophic Tsunami

Earth and possibly its Moon were hit by impactors that killed off the dinosaurs
Artistic rendition of the Chicxulub impactor striking ancient Earth, with Pterosaur observing. Could pieces of the same impact swarm have hit the Moon, too? Credit: NASA

For decades, scientists have theorized that a massive impact caused the Cretaceous-Paleogene extinction event. This event occurred about 66 million years ago and caused the mass extinction of about 75% of all plant and animal species on Earth (including the non-avian dinosaurs). With the discovery of the massive Chicxulub crater in the Yucatan Peninsula (southern Mexico) in the 1970s, scientists concluded that they’d found the impact responsible. Based on all the available data, the Chicxulub Impact event is believed to have been as powerful as 100,000 billion metric tons (110,231 U.S tons) of TNT.

This blast was more powerful than all the nuclear devices in the world combined and sent an estimated 25 trillion metric tons (~27.5 US tons) of hot dust, ash, and steam into the atmosphere, creating a global winter. But according to new research led by the University of Michigan, an international team of geologists has determined that the impact also created a global tsunami. According to their findings, this tsunami was 30,000 times more powerful than the 2004 Indian Ocean tsunami, one of the largest and most devastating tsunamis on record.

Continue reading “The Asteroid That Killed the Dinosaurs Also Flooded the World's Coastlines With a Catastrophic Tsunami”

Astronomers Have Found More Than 30,000 Near-Earth Asteroids… so far

Asteroid hunters have become increasingly good at their job. The discipline, which took a back seat in the early days of astronomy, has really come into its own as of late. Once the general public, probably spurred on by popular 1990s movies like Deep Impact and Armageddon, realized the potentially existential threat they posed, support for finding all asteroids that could be planet killers skyrocketed. At this point, astronomers think that most planet-killing asteroids have been found and have worked their way down to much smaller but still devastating impactors. And now they’ve reached a new milestone with over 30,000 Near Earth Asteroids (NEAs) officially discovered.

Continue reading “Astronomers Have Found More Than 30,000 Near-Earth Asteroids… so far”

Thanks to Hayabusa 2’s Samples, Scientists can Track the History of Ryugu Earlier in the History of the Solar System

When Huyabusa2 returned a sample of Ryugu, a Near Earth Asteroid, to Earth in December 2020, it was sure to light a bonfire of material science research. We’re starting to see the beginning of that, and a new study led by a scientist at Lawrence Livermore National Laboratory has found a particular grain in the sample Huyabusa2 collected that shows how the asteroid formed.

Continue reading “Thanks to Hayabusa 2’s Samples, Scientists can Track the History of Ryugu Earlier in the History of the Solar System”

After Getting Slammed by DART, Asteroid Dimorphos has Grown a Tail

Astronomers using the NSF’s NOIRLab’s SOAR telescope in Chile captured the vast plume of dust and debris blasted from the surface of the asteroid Dimorphos by NASA’s DART spacecraft when it impacted on 26 September 2022. In this image, the more than 10,000 kilometer long dust trail — the ejecta that has been pushed away by the Sun’s radiation pressure, not unlike the tail of a comet — can be seen stretching from the center to the right-hand edge of the field of view.

More images and details keep coming in about the asteroid intentionally smashed by NASA’s Double Asteroid Redirection Test (DART) spacecraft last week, and this latest image is stunning.

A telescope in Chile called SOAR took an image of the asteroid Dimorphos two days after the impact by DART and found the asteroid is trailing a stream of debris more than 10,000 kilometers (6,000 miles) long. However, other reports indicate that the debris trail could now be as long as 50,000 km (31,000 miles), and could still be growing.

Continue reading “After Getting Slammed by DART, Asteroid Dimorphos has Grown a Tail”