A gigantic asteroid has recently passed Earth at a safe distance, but its interaction with our planet is not over.
This coming weekend, the mountain-sized celestial body will reach its maximum brightness in a rare occurrence that happens once every decade, which you can witness from home using standard stargazing binoculars — or through a complimentary livestream.
Designated as (887) Alinda, this near-Earth asteroid spans an estimated 2.6 miles (4.2 kilometers) in diameter — comparable to the width of Manhattan — according to NASA’s Jet Propulsion Laboratory. On Wednesday (Jan. 8), this hefty celestial rock had its closest encounter with Earth in decades, coming as close as 7.6 million miles (12.3 million km) from our planet, or roughly 32 times the average distance separating Earth and the moon. It is expected that Alinda won’t have another close approach to Earth until 2087.
Though an asteroid of this size could lead to a mass extinction event if it were to impact Earth, its significant dimensions also render it an exciting target for eager astronomers. On Sunday (Jan. 12), Alinda will display its brightest point at a magnitude of 9.4. This is not bright enough to be perceived with the unaided eye, but sufficiently luminous to be seen through entry-level stargazing binoculars or a quality backyard telescope, as stated by astronomer Gianluca Masi, who oversees the Virtual Telescope Project in Italy.
The asteroid will be perceptible traversing the constellation Gemini, which becomes visible in the Northern Hemisphere shortly after dusk and remains observable throughout the night, according to skywatching journalist Jamie Carter.
Related: NASA’s most wanted: The 5 most perilous asteroids to Earth
If you lack the necessary equipment, don’t worry; Masi and the Virtual Telescope Project are hosting a complimentary livestream of asteroid Alinda’s radiant passage on Jan. 12 at 12:30 p.m. EST. You can view it on the project’s official YouTube channel or in the video embedded below.
It’s uncommon to observe such a massive entity passing so near to Earth. As per Masi, occurrences like this take place merely once a decade, and Alinda ranks among the five most significant asteroids expected to traverse within 9.3 million miles (15 million km) of our planet until the year 2200.
Fortunately, neither Alinda nor any other identified asteroid presents a hazard to Earth for at least the upcoming century, as stated by NASA. Nevertheless, space agencies take the menace of “planet killer” asteroids with utmost seriousness and are actively assessing various planetary defense strategies. NASA’s recent Double Asteroid Redirection Test (DART) mission demonstrated the capability to alter the trajectory of a large asteroid by colliding a spacecraft with it. However, the execution of actually safeguarding Earth from an imminent asteroid would probably necessitate launching hundreds of rockets concurrently, which would demand years to decades of prior warning, Live Science previously reported. Meanwhile, China is planning to initiate its own asteroid deflection mission by the year 2030.
If luminous asteroids are not your idea of celestial wonders, remain alert for numerous other thrilling stargazing events this month. On Monday (Jan. 13), the full Wolf Moon will ascend beside Mars, seemingly consume the Red Planet while Mars disappears behind the moon for around four hours, prior to reappearing on the opposite side. Later, commencing Jan. 21, a procession of six planets will become visible in Earth’s atmosphere, with Venus, Mars, Jupiter, and Saturn all discernible to the naked eye at night and Uranus and Neptune observable with telescopic aids. The planets will stay in the sky throughout February, with Mercury also participating in the planetary display in early March.