Asteroid 2024 YW8 passs the Earth.

Asteroid 2024 YW8 passed by the Earth at a distance of 28 323 km (0.074 times the average distance between the Earth and the Moon, or 0.0002% of the distance between the Earth and the Sun, but 27 915 km above the altitude at which the International Space Station orbits), with a relative velocity of about 8.83 km per second, slightly after 9.25 pm GMT on Monday 30 December 2024. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2024 YW8 has an estimated equivalent diameter of 1-2 m (i.e. it is estimated that a spherical object with the same volume would be 1-2 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) more than 42 km above the ground, with only fragmentary material reaching the Earth's surface.

30 second image of 2024 YW8 taken with the Elena Planetwave 17" Telescope at Ceccano in Italy on 30 December 2024. The asteroid is the small point at the centre of the image, indicated by the white arrow, the longer lines are stars, their elongation being caused by the telescope tracking the asteroid over the length of the exposure. At the time when the image was taken, the asteroid was about 2.5 million km from the Earth. Gianluca Masi/Virtual Telescope Project.

2024 YW8 was discovered on 30 December 2024 (a few hours before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2024 YW8 implies that the asteroid was the 222nd object (asteroid W8 - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 26, A2 = 51, etc., which means that W8 = (8 x 25) + 22 = 222) discovered in the second half of December 2024 (period 2024 y - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

The relative positions of 2024 YW8 and the Earth at 9.00 pm on Monday 30 December 2024. JPL Small Body Database.

2024 YW8 is calculated to have a 594 day (1.60 year) orbital period, with an elliptical orbit tilted at an angle of 2.19° to the plain of the Solar System which takes in to 0.91 AU from the Sun (91% of the average distance at which the Earth orbits the Sun) and out to 1.82 AU (1.82 times the distance at which the Earth orbits the Sun, more than the distance at which the planet Mars orbits). 

The positions and orbits of 2024 YW8 and the planets of the Inner Solar System at 9.00 pm on Thursday 30 December 2024. JPL Small Body Database.

2024 VW8 is therefore classed as an Apollo Group Asteroid, which is an asteroid that is on average further from the Sun than the Earth, but which does get closer. 2024 VW8 is calculated to have fairly regular close encounters with the Earth, with the last thought to have happened in January 2017 and the next predicted for December 2028. The asteroid is also predicted to have occasional close encounters with the planet Mars, with the next predicted for April 2069.

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Asteroid 2024 RL8 passes the Earth.

Asteroid 2024 RL8 passed by the Earth at a distance of about 329 350 km (1.12 times the average distance between the Earth and the Moon, or 0.29% of the distance between the Earth and the Sun), with a relative velocity of about 13.33 km per second, slightly before 10.40 pm GMT on Wednesday 11 September 2024. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2024 RL8 has an estimated equivalent diameter of 6-19 m (i.e. it is estimated that a spherical object with the same volume would be 6-19 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) between 40 and 22 km above the ground, with only fragmentary material reaching the Earth's surface.

300 second image of 2024 RL8 taken with the Elena Planetwave 17" Telescope at Ceccano in Italy on 9 September 2024. The asteroid is the small point at the centre of the image, indicated by the white arrow, the longer lines are stars, their elongation being caused by the telescope tracking the asteroid over the length of the exposure. At the time when the image was taken, the asteroid was about 2.5 million km from the Earth. Gianluca Masi/Virtual Telescope Project.

2024 RL8 was first detected on 7 September 2024 (four days before its closest approach to the Earth), by the University of Hawaii's PANSTARRS2 telescope. The designation 2025 RL8 implies that it was the 211th asteroid (asteroid L8 - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 25, A2 = 49, etc., which means that L8 = (25 x 8) + 11 = 211) discovered in the first half of September 2024 (period 2024 R; the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

The relative positions of 2024 RL8 and the Earth on at 11.00 pm on Wednesday 11 September 2024. JPL Small Body Database.

2024 RL8 is calculated to have a 480 day (1.31 year) orbital period, with an elliptical orbit tilted at an angle of 12.01° to the plain of the Solar System which takes in to 0.71 AU from the Sun (71% of the average distance at which the Earth orbits the Sun, and slightly inside the orbit of Venus) and out to 1.69 AU (1.69 times the distance at which the Earth orbits the Sun, more than the distance at which the planet Mars orbits). 

The positions and orbits of 2024 RL8 and the planets of the Inner Solar System at 11.00 pm on Wednesday 11 September 2024. JPL Small Body Database.

2024 RL8 is therefore classed as an Apollo Group Asteroid, which is an asteroid that is on average further from the Sun than the Earth, but which does get closer. 2024 RL8 is calculated to have fairly regular close encounters with the Earth, with the last thought to have happened in September 2020 and the next predicted for August 2028. The asteroid is also predicted to have regular close encounters with the planet Venus, with the last thought to have happened in June 2019 and the next predicted for June 2027.

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Asteroid 2024 RW1 impacts the Earth.

On the morning of Wednesday 4 September 2024, planetary scientist Jacqueline Fazekas working at the University of Arizona's Catalina Sky Survey detected a fast moving object, which she interpreted as a potential Near Earth Asteroid. She reported this to the International Astronomical Union's Minor Planet Center, where it was given the provisional designation CAQTDL2. This initial discovery was followed by a series of further sightings from other observatories, confirming that the object was an asteroid, which was then named 2024 RW1, and that it was on a collision course with the Earth.

Discovery images of Asteroid 2024, within purple circles. Catalina Sky Survey.

The designation 2024 RW1 implies that the asteroid was the 47th asteroid  (asteroid W1 - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 26, A2 = 51, etc., which means that W1 = (25 x 1) + 22 = 47) discovered in the first half of September 2024 (period 2024 R - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

Asteroid 2024 RW1 is calculated to have had a 1450 day (3.97 year) orbital period, with an elliptical orbit tilted at an angle of 0.53° to the plain of the Solar System which took in to 0.74 AU from the Sun (74% of the distance at which the Earth orbits the Sun) and out to 4.23 AU (4.23 times the distance at which the Earth orbits the Sun, and almost three times the distance at which the planet Mars orbits). It is therefore classed as having been an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). 

The calculated orbit of asteroid 2024 RW1. JPL Small Body Database.

Asteroid 2024 BX1 is calculated to have had four close encounters with the Earth before finally impacting, with the first in August 1912, and the most recent in October 2020. It has also had close encounters with Venus in June 1966 and January 2009, and Jupiter in November 2006 and September 2018. Asteroids which make close passes to multiple planets are considered to be in unstable orbits, and are often eventually knocked out of these orbits by these encounters, either being knocked onto a new, more stable orbit, dropped into the Sun, knocked out of the Solar System or occasionally colliding with a planet.

By 11.00 am GMT on 4 September 2024, the European Space Agency had calculated that Asteroid 2024 RW1 would impact the Earth, entering the atmosphere at about 5.08 pm over or close to northern Luzon Island, the Philippines. In the event the asteroid entered the atmosphere at 4.46 pm GMT (0.46 am on 5 September, Philippines time) over the Pacific Ocean to the east of Luzon, producing a bright fireball meteor, with a distinct green colour, which probably indicates that it had a high magnesium content. 

A bright fireball meteor observed from Tuguegarao City in the Philippines on 5 September 2024, thought to have been caused by the impact of Asteroid 2024 RW1. Marvin Coloma/American Meteor Society.

Objects of this size probably enter the Earth's atmosphere several times a year, though unless they do so over populated areas they are unlikely to be noticed. They are officially described as fireballs if they produce a light brighter than the planet Venus. It is possible on this occasion the object is known to have produced meteorites that reached the surface (an object visible in the sky is a meteor, a rock that falls from the sky and can be physically held and examined is a meteorite).

Based upon observations in space and on entry to the Earth's atmosphere, 2024 RW1 is calculated to have been about a metre in diameter, and to have had a high magnesium content, something which in turn implies a stony meteorite rich in the mineral olivine (counter to possible expectations, metallic meteorites seldom contain much magnesium). However, as it fell to Earth over the Pacific Ocean, it is unlikely that any fragments of the asteroid will be recovered to test this hypothesis. 2024 RW1 is the eighth asteroid ever to have been discovered before impacting the Earth.

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Potentially Hazardous Asteroid 2024 HP passes the Earth.

Asteroid 2024 HP passed by the Earth at a distance of about 592 000 km (15.4 times the average distance between the Earth and the Moon, or 3.96% of the distance between the Earth and the Sun), with a relative velocity of about 7.67 km per second, slightly before 5.00 pm GMT on Thursday 23 May 2024. There was no danger of the asteroid hitting us, though were it to do so it would have presented a significant threat. 2024 HP has an estimated equivalent diameter of 160-350 m (i.e. it is estimated that a spherical object with the same volume would be 160-350 m in diameter), and an object of this size would be expected to penetrate the Earth's atmosphere and impact  the Earth's surface, causing an explosion with an equivalent energy release to between 1.5 and  12.8 megatons of TNT. An impact at the lower end of this range would be expected to flatten forests and man-made structures over a significant distance, while one at the upper end of the range could cause a crater 2.87 km in diameter and global climatic effects which would persist for decades if not centuries.

300 second image of 2024 JN16 taken with the Celestron 14"-F8/8.4 (356/3000 mm) Schmidt-Cassegrain Telescope at Ceccano in Italy on 28 May 2024, when the asteroid was 6.8 million km from the Earth, and moving away. The asteroid is the small point at the centre of the image, indicated by the white arrow, the longer lines are stars, their elongation being caused by the telescope tracking the asteroid over the length of the exposure. Gianluca Masi/Virtual Telescope Project.

2024 HP was discovered on 17 April 2024 (36 days before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2024 HP implies that the asteroid was the fifteenth object (asteroid P - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 26, A2 = 51, etc., which means that P = 15) discovered in the second half of April 2024 (period 2024 H - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

The relative positions of 2024 HP and the Earth at 5.00 pm on Thursday 23 May 2024. JPL Small Body Database.

2024 HP is calculated to have a 983 day (2.69 year) orbital period, with an elliptical orbit tilted at an angle of 6.53° to the plain of the Solar System which takes in to 1.01 AU from the Sun (101% of the average distance at which the Earth orbits the Sun) and out to 2.85 AU (2.85 times the distance at which the Earth orbits the Sun, almost twice the distance at which the planet Mars orbits). 

The positions and orbits of 2024 HP and the planets of the Inner Solar System at 5.00 pm on Thursday 23 May 2024. JPL Small Body Database.

2024 HP is therefore classed as an Apollo Group Asteroid, which is an asteroid that is on average further from the Sun than the Earth, but which does get closer (1.01 AU from the Sun would appear to be further from the Sun than the Earth, which is, on average 1.00 AU from the Sun, but at aphelion, which happens in July each year, the Earth reaches almost 1.02 AU from the Sun). As an asteroid possibly larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, 2024 HP is also classified as a Potentially Hazardous Asteroid.

2024 HP is calculated to have fairly regular close encounters with the Earth, with the last thought to have happened in April 2016 and the next predicted for August 2032.

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Asteroid 2024 JN16 passes the Earth.

Asteroid 2024 JN16 passed by the Earth at a distance of about 25 400 km (0.07 times the average distance between the Earth and the Moon, or 0.017% of the distance between the Earth and the Sun, but more than 62 times as far from the Earth's surface as the International Space Station), with a relative velocity of about 9.26 km per second, slightly before 9.50 am GMT on Tuesday 14 May 2024. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2024 JN16 has an estimated equivalent diameter of 2-7 m (i.e. it is estimated that a spherical object with the same volume would be 2-7 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) more than 36 km above the ground, with only fragmentary material reaching the Earth's surface.

120 second image of 2024 JN16 taken with the Celestron 14"-F8/8.4 (356/3000 mm) Schmidt-Cassegrain Telescope at Ceccano in Italy on 5 April 2020. The asteroid is the small point at the centre of the image, indicated by the white arrow, the longer lines are stars, their elongation being caused by the telescope tracking the asteroid over the length of the exposure. Gianluca Masi/Virtual Telescope Project.

2024 JN16 was discovered on 12 May 2024 (two days before its closest approach to the Earth) by Gennady Borisov at the MARGO observatory in Crimea. The designation 2024 JN16 implies that it was the 638th asteroid (object N16 - in numbering asteroids the letters A-Y, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended so that A = 1, A1 = 26, A2 = 51, etc., which means that N16 = 13 + (25 x 16) = 638) discovered in the first half of May 2024 (period 2024 J - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

The relative positions of 2024 JN16 and the Earth on at 10.00 am GMT on 14 May 2024. JPL Small Body Database.

2024 JN16 is calculated to have a 456 day (1.25 year) orbital period, with an elliptical orbit tilted at an angle of 5.79° to the plain of the Solar System which takes in to 0.89 AU from the Sun (89% of the distance at which the Earth orbits the Sun) and out to 1.43 AU (1.43 times the distance at which the Earth orbits the Sun, somewhat less than the distance at which the planet Mars orbits). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). 

The relative positions of 2024 JN16, the Earth, and the planets of the Inner Solar System on at 10.00 am GMT on 14 May 2024. JPL Small Body Database.

This means that 2024 JN16 has regular close encounters with the Earth, with the last calculated to have happened in November 2019, and the next predicted for January 2032. 2024 JN16 also has occasional close encounters with the planet Venus, with the next predicted for June 2025.

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