Two large asteroids to pass Earth in close succession

Two large asteroids to pass Earth in close succession
by Erica Marchand
Paris, France (SPX) Jun 25, 2024
Two large asteroids will safely pass Earth this week, coinciding with this year's Asteroid Day. Neither poses any risk to our planet, but one of them was only discovered a week ago, underscoring the need to enhance our detection capabilities for potentially hazardous objects.

Asteroid 2024 MK, measuring between 120 and 260 meters, was discovered on 16 June 2024. It will fly past Earth on 29 June during Asteroid Day events.

This near-Earth object (NEO) will pass within 290,000 km of Earth's surface, about 75% of the distance to the Moon. Although 2024 MK poses no threat, its recent discovery highlights the importance of improving our detection and monitoring systems for potentially hazardous NEOs.

Amateur astronomers can observe 2024 MK on 29 June with a small telescope in certain areas. Observation plans can be made using ESA's NEO toolkit.

(415029) 2011 UL21 - a massive visitor
Asteroid (415029) 2011 UL21, at 2310 meters, is larger than 99% of known near-Earth objects. On 27 June, it will pass at a distance more than 17 times the distance to the Moon.

This asteroid's orbit around the Sun is highly inclined, unusual for such a large object. This inclination could be due to gravitational interactions with a large planet like Jupiter, which can redirect asteroids towards Earth. Understanding these interactions is crucial.

(415029) 2011 UL21 is in an '11:34 resonance' with Earth, completing 11 orbits around the Sun in the same time it takes Earth to complete 34 orbits, forming a repeating pattern over 34 years.

Asteroid Day 2024
Asteroid Day, endorsed by the UN, commemorates the 1908 Tunguska event, the largest recorded asteroid strike. The event emphasizes the importance of planetary defense.

ESA, with its Member States, coordinates efforts to understand and respond to asteroid hazards. Over the past two decades, ESA has focused on detecting and analyzing potentially hazardous NEOs, estimated to number around 5 million above 20 meters in size.

ESA's asteroid defense initiatives
ESA's Planetary Defence Office is engaged in projects to improve detection, tracking, and mitigation of hazardous asteroids. Later this year, ESA will launch the Hera mission, part of the first asteroid deflection test. Hera will study the asteroid Dimorphos following NASA's DART mission impact in 2022, aiming to develop a repeatable planetary defense technique. The Hera team will participate in Asteroid Day celebrations.

On Earth, ESA is developing Flyeye telescopes with wide fields of view to scan the sky nightly for new hazardous asteroids. The future NEOMIR satellite, positioned between Earth and the Sun, will use infrared to detect asteroids obscured by the Sun's glare.

ESA's Planetary Defence Office continues to monitor the sky. Recently, ESA's fireball camera in Caceres, Spain, captured a meteor on 18-19 May 2024, likely a small comet fragment. On 6 June 2024, the Catalina Sky Survey discovered a small asteroid that triggered ESA's Meerkat alert system, marking the second closest pass of a non-impacting asteroid ever recorded.