When we look at the Moon, either through a pair of binoculars, a telescope, or past footage from the Apollo missions, we see a landscape that’s riddled with what appear to be massive sinkholes. But these “sinkholes” aren’t just on the Moon, as they are evident on nearly every planetary body throughout the solar system, from planets, to other moons, to asteroids. They are called impact craters and can range in size from cities to small countries.
Continue reading “Impact Craters: Why study them and can they help us find life elsewhere?”DART Showed We Can Move an Asteroid. Can We Do It More Efficiently?
Like many of you, I loved Deep Impact and Armageddon. Great films, loads of action and of course, an asteroid on collision course with Earth. What more is there to love! Both movies touched upon the options for humanity to try and avoid such a collision but the reality is a little less Hollywood. One of the most common options is to try some sort of single impact style event as was demonstrated by the DART (Double Asteroid Redirection Test) mission but a new paper offer an intriguing and perhaps more efficient alternative.
Continue reading “DART Showed We Can Move an Asteroid. Can We Do It More Efficiently?”If You’re Trying to Prevent an Asteroid Impact, the Technical and Political Challenges are Staggering
While preparing for the threat of an asteroid strike might seem like a hypothetical exercise, it’s really not. The Solar System has calmed down a lot from earlier times when impacts were more frequent. But it is only a matter of time before an asteroid heads straight for Earth. The probability of an impact is not zero.
Equally as difficult as determining when one will come for us is the task of getting humanity to cooperate and prepare for it.
Continue reading “If You’re Trying to Prevent an Asteroid Impact, the Technical and Political Challenges are Staggering”Astronomers See the Afterglow Where Two Ice Giant Planets Collided
What would happen if two giant planets collided? It would be terrifying to behold if it happened in our Solar System. Imagine if Neptune and Uranus slammed into each other. Picture the chaos as a new super-heated object took their places, and clouds of debris blocked out the Sun. Think of the monumental destruction as objects are sent careening into each other.
Astronomers spotted the aftermath of a gigantic planetary collision like this in a distant solar system. From a safe distance, they were surprised and intrigued rather than terrified. Now, they intend to keep watching as the aftermath unfolds.
Continue reading “Astronomers See the Afterglow Where Two Ice Giant Planets Collided”Did Powerful Asteroid Impacts Make Venus So Different From Earth?
Venus and Earth have several things in common. Both are terrestrial planets composed of silicate minerals and metals that are differentiated between a rocky mantle and crust and a metal core. Like Earth, Venus orbits within our Sun’s circumsolar habitable zone (HZ), though Venus skirts the inner edge of it. And according to a growing body of evidence, Venus has active volcanoes on its surface that contribute to atmospheric phenomena (like lightning). However, that’s where the similarities end, and some rather stark differences set in.
In addition to Venus’ hellish atmosphere, which is about 100 times as dense as Earth’s and hot enough to melt lead, Venus has a very “youthful” surface. Compared to other bodies in the Solar System (like Mercury, the Moon, and Mars), Venus’ surface retains little evidence of the many bolides impacts it experienced over billions of years. According to new research from the Southwest Research Institute (SwRI) and Yale University, this may result from bolide impacts that provided a high-energy, rejuvenating boost to the planet in its early years.
Continue reading “Did Powerful Asteroid Impacts Make Venus So Different From Earth?”Not All Craters are Circular. Sometimes They Look Like This
Impact craters are nature’s signature from a more chaotic time in our Solar System’s history. A quick glance at the Moon’s disfigured surface makes that clear. Same with Mars, though a telescope is needed to examine it. Or better yet, an orbital spacecraft with a powerful camera.
The Mars Reconnaissance Orbiter and its HiRISE camera have been examining Mars’ surface for years, cataloguing the planet’s menagerie of impact craters. One of them, recently chosen as the HiRISE Picture of the Day (HIPOD,) looks like a Thunderbird. Or a dinosaur footprint left in the mud.
Continue reading “Not All Craters are Circular. Sometimes They Look Like This”Is This Nearby Asteroid a Chunk of the Moon?
The Moon dominates our view of the night sky. But it’s not the only thing orbiting Earth. A small number of what scientists call quasi-satellites also orbit Earth.
One of them is called Kamo’oalewa, and it’s a near-Earth asteroid. It’s similar to the Moon in some respects. Could it be a chunk of the Moon?
Continue reading “Is This Nearby Asteroid a Chunk of the Moon?”Watch the Chelyabinsk Meteor Breakup in this Detailed Simulation
The people of Chelyabinsk in Russia got the surprise of their lives on the morning of February 15, 2013. That’s when a small asteroid exploded overhead. The resulting shockwave damaged buildings, injured people, and sent a sonic boom thundering across the region.
Continue reading “Watch the Chelyabinsk Meteor Breakup in this Detailed Simulation”Recreating the Extreme Forces of an Asteroid Impact in the Lab
About 50,000 years ago, a nickel-iron meteorite some 50 meters across plowed into the Pleistocene-era grasslands of what is now Northern Arizona. It was traveling fast—about 13 kilometers per second. In just a few seconds, an impact dug out a crater just over a kilometer wide and spread rocks from the site for miles around.
Continue reading “Recreating the Extreme Forces of an Asteroid Impact in the Lab”Should Planetary Defence Take Center Stage?
Throughout the Solar System, planets and moons bear the scars of a past fraught with collisions. The Moon, Mercury, and Mars are so scarred from these impacts that craters overlap one another on their surfaces. Earth was subject to the same bombardment, though most of its impact scars disappeared over time due to active geology.
But some are still visible, and we know how catastrophic some of these impacts were for life.
Continue reading “Should Planetary Defence Take Center Stage?”