An asteroid about the size of a small building zoomed past Earth unnoticed by astronomers last week, coming as close to the Earth’s surface as the International Space Station, according to the European Space Agency.
The space rock dubbed 2025 TF was spotted hours after it flew past Antarctica by the Nasa-funded Catalina Sky Survey, which uses telescopes in Arizona and Australia to spot near-Earth objects.
European astronomers then observed it using the Las Cumbres Observatory telescope in Siding Spring, Australia.
Astronomers estimated that the asteroid came as close as 428km (265 miles) to Earth’s surface.
"This is a similar altitude to the orbit of the International Space Station, and one of the closest approaches ever recorded," the ESA said in a statement.
Most satellites go around the planet at low-Earth orbits of between 160 km (100 miles) and 2000 km (1,243 miles).
The ESA said the asteroid measured somewhere between one and three metres across.
"Tracking down a metre-scale object in the vast darkness of space at a time when its location is still uncertain is an impressive feat," ESA said.
"This observation helped astronomers determine the close approach distance and time given above to such high precision,” it added.
Another small asteroid dubbed 2025 TQ2 also flew within Earth's vicinity the same day after 2025 TF's approach, according to the Minor Planet Center, an international organisation tracking asteroids, comets, and other small bodies.
This asteroid reportedly zoomed past Earth over Canada at a distance of about 4,850 km (3,014 miles), which is less than half the Earth’s diameter, according to EarthSky.org.
While asteroids and other space objects of such sizes do not pose any significant danger to life and property on Earth, they can produce fireballs if they strike the planet’s atmosphere.
Space agencies across the world are continuously tracking such near-Earth objects, and they are categorised as “potentially hazardous” to the planet if they are larger than 150m (500 ft) and projected to get closer than about 7.5 million km (4.65 million miles) to Earth.
Smaller asteroids can still do significant damage, however. The 65 metre-long (300ft) asteroid 2024 YR4, spotted last year and predicted to have a small chance of striking the Moon, could wipe out an entire city if it struck the Earth, astronomers say.
While it is in fact predicted to miss our planet, it has a 4 per cent chance of crashing onto the Moon in December 2032 and kicking up lunar dust and debris, which could threaten satellites around Earth.
Researchers predict the asteroid may generate a lunar debris cloud weighing over 100,000,000 kg, which could “accrete to the Earth on timescales of a few days” and expose satellites orbiting the Earth to meteorites for years.
Astronomers recently proposed planning a mission to blow up the asteroid using nuclear explosives to cut the risk of its Moon collision debris destroying satellites.
