Just before dawn on 22 February 2021, a fireball lit up the skies across Canada's Alberta (see video below) province when a 2-kilogram space rock vaporized as it plunged through Earth's atmosphere. Although the object hailed from the Oort Cloud — a conglomeration of comets at the edge of the Solar System — it wasn't a comet, researchers now say. Data collected during its fall suggest the object was made of rock rather than ice and behaved more like an asteroid.

Independent observers of the new work say the find sheds light on the processes that formed our Solar System and challenges the conventional wisdom that the Oort Cloud only holds icy comets. "It's telling us that there was scattering and depositing of material from all over the Solar System into the Oort Cloud," says Karen Meech, a planetary scientist at the University of Hawaii's Institute for Astronomy.

The discovery could provide support for models that suggest objects from the asteroid belt were dispersed into the Oort Cloud soon after the Solar System's birth 4.6 billion years ago, says Bill Bottke, a Solar System dynamicist at the Southwest Research Institute. "This is very exciting," he says. "Now, we have to see what we can do to explain it."

First proposed by Dutch astronomer Jan Oort in 1950, the Oort Cloud is a spherical halo of comets that stretches out halfway to Proxima Centauri, the Sun's nearest neighbor, well beyond the view of even the largest telescopes. "Everything we know about it is indirect," says Denis Vida, a meteor astronomer at Western University who led the new study.

Scientists presume the Oort Cloud became populated with comets when the gravitational muscle of Jupiter and the other giant planets scattered far and wide the icy objects that were leftover from the formation of the outer Solar System. Occasionally, a passing star will gravitationally nudge an Oort Cloud object and send it plummeting into the inner Solar System. These objects are known as long-period comets, defined by their eccentric paths that take hundreds or even thousands of years to orbit the Sun.

We have now discovered 30,039 near-Earth asteroids in the Solar System - rocky bodies orbiting the Sun on a path that brings them close to Earth's orbit. The majority of these were discovered in the last decade, showing how our ability to detect potentially risky asteroids is rapidly improving.

In-depth What is a near-Earth asteroid?

The first probable impact crater in Spain has been identified in the southern province of Almeria. The discovery was presented last week at the Europlanet Science Congress (EPSC) 2022 by Juan Antonio Sánchez Garrido of the University of Almeria.

While around 200 impact structures have been identified around the world, the study is the first to identify signs of an impact crater on the Iberian Peninsula. The discovery is the result of 15 years of research by an international team of scientists from the University of Almeria, the Astrobiology Center of Madrid, the University of Lund and the University of Copenhagen.

Prof Sánchez Garrido said: "We believe that the impact event occurred around 8 million years ago. We have investigated numerous aspects of the geology, minerology, geochemistry and geomorphology of the region. The basins of Alhabia and Tabernas in the area are filled with sediments dating back between 5 and 23 million years, and they overlie older metamorphic rocks. Much of the impact structure is buried by more modern sediments, but erosion has exposed it and opened up the opportunity for studies."

The crater itself is thought to be about 4 kilometres in diameter, and it is surrounded by a larger structure about 20 kilometres across where the impact caused the sedimentary strata to collapse.

NASA has completed a key step of its "Double Asteroid Redirection Test" (DART), smashing a satellite roughly the size of a vending machine into a small moon that's about half-a-mile in diameter. The moon, Dimorphos, is orbiting an even larger asteroid, Didymos, and while neither is in any danger of colliding with Earth, they're good test cases to see whether us puny humans smashing them with technology can cause them to change course.

The meteorite that wiped out Earth's dinosaurs instantly ignited forest wildfires up to thousands of kilometres from its impact zone, scientists have discovered.

The six-mile-wide meteorite struck the Yucatan peninsula in what is now Mexico at the end of the Cretaceous Period 66 million years ago, triggering a mass extinction that killed off more than 75 percent of living species.

Uncertainty and debate have surrounded the circumstances behind the devastating wildfires known to have been caused by the strike, with several theories as to how and when they started, and their full extent.

By analysing rocks dating to the time of the strike, a team of geoscientists from the UK, Mexico and Brazil has recently discovered that some of the fires broke out within minutes, at most, of the impact, in areas stretching up to 2500km or more from the impact crater.

Wildfires that broke out in coastal areas were short-lived, as the backwash from the mega-tsunami caused by the impact swept charred trees offshore.

An asteroid wider than two football fields will zoom past Earth in the wee hours of Thursday (Aug. 4). The asteroid is set to pass at 12:23 a.m. (ET).

NASA astronomers discovered the asteroid, known as 2022 OE2, just days ago, on July 26. The meaty space rock is estimated to measure between 557 and 1,246 feet (170 to 380 meters) wide, which is about twice as wide as an American football field is long. Astronomers also confirmed that 2022 OE2 is an Apollo-class asteroid, which means it orbits the sun and crosses the path of Earth's orbit, Live Science previously reported. (Astronomers know of about 15,000 such asteroids.)

The impact from an asteroid this large would release more energy than 1,000 nuclear bombs. However, this one will miss Earth by a wide margin, according to NASA's Jet Propulsion Laboratory.

Asteroid 2022 OE2 is predicted to pass Earth at a distance of roughly 3.2 million miles (5.1 million kilometers) — more than 13 times the average distance between Earth and the moon. For context, this is significantly farther than the asteroid 2022 NF, which came within a mere 56,000 miles (90,000 km) — or about 23% the average distance between Earth and the moon — on July 7.

An animation video shows the giant Comet coming very close to Earth and then moving towards the moon.
A giant comet C/2017 K2 is likely to make a close approach to Earth this month on July 14, 2022. The comet was first discovered in 2017 by Nasa's Hubble Space Telescope hurtling somewhere between Saturn and Uranus. Now it is approaching Earth and the inner solar system at a distance of around 270 million km. Though it does not pose any threat to our planet, an animation video published by specialist Hazegrayart last week shows the comet coming close to our planet and then getting pulled toward the Moon, and impacting it with its full force. However, nothing can be confirmed as yet.

Meanwhile, skywatchers will be able to see the comet by using a small telescope. C/2017 K2 (PanSTARRS) has been traveling from the Oort cloud to the inner solar system and it will be so active and bright that it could be detectable from Earth. The comet relies on energy from the Sun to heat up gasses. Here's all you need to know about Oort cloud and how to spot Comet C/2017 K2 from earth.

Deep within the Sahara Desert lies one of the best-preserved craters on Earth. On Asteroid Day, the Copernicus Sentinel-2 mission takes us over the almost-perfectly circular Tenoumer Crater in Mauritania.

Tenoumer Crater, visible in the centre of the image, is 1.9 km wide. The rims of the crater rise some 110 m high above the base, but the bottom of the crater is covered with approximately 200 to 300 m thick layer of sediments.

It was long debated whether the crater was formed by a volcano or meteorite. Scattered rocks around the crater, similar to basalt, created the impression of an ancient volcano. Yet a closer exanimation of the structure revealed the crater's hardened 'lava' was actually rock that had melted by a meteorite impact.

The crater sits in a vast plain of rocks that are so ancient they were deposited hundreds of millions of years before the first dinosaurs walked Earth. Even though it resides in ancient rock, Tenoumer is much younger, ranging in age between 10 000 and 30 000 years old.

CBET 5121 & MPEC 2022-J88 , issued on 2022, May 11, announce the discovery of a comet (magnitude ~18) by A. Maury and G. Attard on images obtained with a 0.28-m f/2.2 Schmidt reflector at San Pedro de Atacama, Chile, on May 5. The new comet has been designated C/2022 J1 (Maury-Attard).

Stacking of 15 luminance-filtered exposures, 60 seconds each, obtained remotely (in poor conditions, high clouds) on 2022, May 6.4 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a diffuse coma of size about 12" and magnitude of 18.3-18.9 in an aperture radius of 5".5 (Observers E. Bryssinck, M. Rocchetto, E. Guido, M. Fulle, G. Milani, G. Savini, A. Valvasori).

Our confirmation image (click on the images for a bigger version)
CBET 5121 assigns the following parabolic orbital elements to comet C/2022 J1 (Maury-Attard): T 2022 Feb. 21.59; e= 1.0; Peri. = 307.65; q =1.63; Incl.= 106.45 (It is possible that the comet has a periodic orbit on the order of 120 years or so).

For the past 3 million years, Comet C/2017 K2 (PanSTARRS) has been falling toward the sun, a long, slow journey from the outer solar system. Finally, it's here. Michael Jaeger photographed it on June 25th from Martinsberg, Austria:
"This is a 22-minute exposure with my 16-inch telescope," says Jaeger. "The comet was about 9th magnitude."