Asteroid 2026 EM passes the Earth.

Asteroid 2026 EM passed by the Earth at a distance of about 28 424 km (7% of the average distance between the Earth and the Moon, or 0.02% of the distance between the Earth and the Sun, but 71 times the distance at which the International Space Station orbits the Earth), at about 7.45 pm GMT on Monday 7 March 2026. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. Asteroid 2026 EM has an estimated equivalent diameter of 1-3 m (i.e. it is estimated that a spherical object with the same volume would be 1-3 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 (if that) reaching the Earth's surface.

The relative positions of 2026 EM, the Earth, and the Moon at 8.00 pm on Monday 7 March 2026. JPL Small Body Database.

2026 EM was discovered on 6 March 2026 (the day of its closest approach to the Earth) by the University of Szeged's Szeged Asteroid Program, which is located at the Piszkéstető Mountain Station in the Mátra Mountains to the northeast of Budapest. The designation 2022 EM implies that it was the 12th asteroid (object M - 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 M implies the 12th asteroid) discovered in the first half of March 2026 (period 2026 E - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

The relative positions of 2026 EM, the Earth, and the planets of the Inner Solar System at 8.00 pm on Monday 7 March 2026. JPL Small Body Database.

2026 EM has a 425 day (1.16 year) orbital period, with an elliptical orbit tilted at an angle of 4.77° 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 1.32 AU (132% of the distance at which the Earth orbits the Sun). 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). This means that Asteroid 2026 EM has occasional close encounters with the Earth, with the most recent having happened in March 2019, and the next predicted for March 2039. The asteroid also has occasional close encounters with the planet Mars, with the next such encounter predicted for May 2032.

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Asteroid (242708) 2005 UK1 passes the Earth.

Asteroid (242708) 2005 UK1 passed by the Earth at a distance of about 12 355 300 km (32.2 times the average distance between the Earth and the Moon, or 8.26% of the distance between the Earth and the Sun), slightly after 10.25 am GMT on Monday 12 January 2026. There was no danger of the asteroid hitting us, though were it to do so it would have presented a significant threat. Asteroid (242708) 2005 UK1 has an estimated equivalent diameter of 450-1400 m (i.e. it is estimated that a spherical object with the same volume would be 450-1400 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 of more than 4000 megatons of TNT. An impact of this size would be expected to flatten forests and man-made structures over thousands of kilometres, while producing a crater at least 6 km in diameter and probably significantly larger, as well as causing global climatic effects which would persist for decades if not centuries.

120 second image of (242708) 2005 UK1 taken with the Elena Planetwave 17" Telescope at Ceccano in Italy on Sunday 11 March 2026. The asteroid is the small point at the centre of the image, 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.

(242708) 2005 UK1 was discovered on 24 October 2005 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 2005 UK1 implies that the asteroid was the 35th object (asteroid K1 - 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 K1 = 25 + 10 = 25) discovered in the second half of October 2005 (period 2005 K - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

(242708) 2005 UK1 is calculated to have a 1445 day (3.96 year) orbital period, with an elliptical orbit tilted at an angle of 0.79° to the plain of the Solar System which takes in to 0.79 AU from the Sun (79% of the average distance at which the Earth orbits the Sun) and out to 4.24 AU (4.24 times the distance at which the Earth orbits the Sun, almost three times the distance at which the planet Mars orbits). 

The positions and orbits of Asteroid (242708) 2005 UK1 and the planets of the Inner Solar System at 10.00 am on Monday 12 January 2026. JPL Small Body Database.

(242708) 2005 UK1 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. As an asteroid possibly larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, (242708) 2005 UK1 is also classified as a Potentially Hazardous Asteroid.

Close encounters between (242708) 2005 UK1 and Earth are fairly common, with the last thought to have happened in April 2018 and the next predicted in December 2029. (242708) 2005 UK1  also has frequent close encounters with other planets, the last being an encounter with Venus in September 1974, and the next predicted being an encounter with Mars in February 2133.

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The Geminid Meteor Shower.

The Geminid Meteor Shower is expected to peak at about 2.00 am GMT on Saturday 14 December this year (2025) with potentially up to 120 meteors per hour being visible in areas of the Northern Hemisphere with a clear sky. This year, peak activity for the shower coincides with a Waning Crescent Moon, which should not significantly hamper viewing. The meteors appear to radiate from a point in the constellation of Gemini, hence their name.

The radiant point of the Geminid Meteor Shower. Astronomy Now.

Typically, meteor streams are thought to come from dust shed by comets as they come close to the Sun and their icy surfaces begin to evaporate away. Although the dust is separated from the comet, it continues to orbit the Sun on roughly the same orbital path, creating a visible meteor shower when the Earth crosses that path, and flecks of dust burn in the upper atmosphere, due to friction with the atmosphere.

The Earth passing through a stream of comet dust, resulting in a meteor shower. Not to scale. Astro Bob.

Oddly for a meteor shower, the Geminids do not appear to be related to a comet, but instead are associated with an object called 3200 Phaethon, which is classed as an Apollo Asteroid (an asteroid with an orbit that crosses that of the Earth). 3200 Phaethon has a highly elliptical orbit, which takes it in as close as 0.14 Au (14% of the distance between the Earth and the Sun, more than twice as close as Mercury) and out as far as 2.4 AU (2.4 times as far from the Sun as the Earth or 1.6 times as far as Mars). 3200 Phaethon does not appear to produce any sort of halo (a cloud of material produced by the evaporation of gas ice from the surface of a comet, thought to be the source of most meteor showers); rather it appears dark in colour an is classed as a B-type Carbonaceous Asteroid, thought to have a surface covering of  anhydrous silicates, hydrated clay minerals, organic polymers, magnetite, and sulphides.

Animation made from images of 3200 Phaeton captured on 17 December 2017, when it was at the closest point of its orbit to Earth, from the Arecibo Observatory in Puerto Rico. National Science Foundation/NASA/Wikimedia Commons.

Asteroid 3200 Phaethon is a 5 km body with a highly eccentric orbit similar to that of a comet, which takes it closer to the Sun than any other named Asteroid. It appears to be the parent body of the Geminid Meteors, which share essentially the same orbit as it, as well as a group of larger bodies known as the Phaethon-Geminid Complex. Such meteor showers typically form from the tail of a comet; as the comet approaches its perihelion (the closest point in its orbit to the Sun), ice at the surface sublimates away (turns directly from a solid to a gas - liquids do not form in a vacuum), releasing particles of silica trapped in the ice, which continue to follow essentially the same path as the comet, creating a meteor shower every time the Earth passes through this stream. 

However, 3200 Phaethon, which has a 1.43 year orbital period in which it reaches 0.14 AU from the Sun (14% of the distance between the Earth and the Sun, or less than half the distance at which Mercury orbits) is thought to regularly suffer surface temperatures in excess of 1000 K, making it highly unlikely that it has ice on its surface, which calls its potential role as the parent body to the Geminid Meteors into question. 3200 Phaethon is classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). As an asteroid probably larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, it is also classified as a Potentially Hazardous Asteroid.

The orbit of 3200 Phaethon, and its position at 2.00 am GMT on 14 December 2025. JPL Small Body Database.

In a paper published in The Astrophysical Journal Letters on 26 June 2013, David Jewitt of the Department of Earth and Space Sciences and Department of Physics and Astronomy at the University of California Los Angeles, Jing Li, also of the Department of Earth and Space Sciences at the University of California Los Angeles, and Jessica Agarwal, then of the Max Planck Institute for Solar System Research, describe the results of a study of 3200 Phaeton using the STEREO Spacecraft.

Jewitt et al. observed two successive perihelions of 3200 Phaeton, in June 2009 and May 2012. On both occasions they were able to observe a faint comet-like dust tail emerging from the body, even though it was apparently reaching temperatures that would rapidly destroy an icy comet. This tail grew rapidly, reaching a length of over 250 000 km within a day of first appearing, and appeared to represent material being lost from the parent body at a rate of about 3 kg per second.

Composite images of 3200 Phaethon in 2009 (top row) and 2012 (bottom row) compared with the projected sun- comet line (white). The Sun is to the upper right in each panel. Insets are 49000 square and show field stars near to Phaethon to demonstrate the point spread function of the data. Each panel has North to the top, East to the left and shows the median of 30 images taken over a 1 day period. Jewitt et al. (2013).

Jewitt et al. suggest that at it's perihelion 3200 Phaethon is being heated to such a degree that hydrated minerals at its surface could be thermally fractured and desiccated, leading to the ejection of dust particles.

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Asteroid 2025 TC passes the Earth.

Asteroid 2025 TC passed by the Earth at a distance of 85 271 km (22% of the average distance between the Earth and the Moon, or 0.000 57% of the distance between the Earth and the Sun, but more than 200 times the altitude at which the International Space Station orbits, and more than double the distance at which geostationary satellites orbit), with a relative velocity of about 16.15 km per second, slightly before 6.35 am GMT on Friday 3 October 2025. 

The relative positions of 2025 TC, the Earth, and the Moon at 6.00 am on Friday 3 October 2025. JPL Small Body Database.

There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2025 TC has an estimated equivalent diameter of 7-23 m (i.e. it is estimated that a spherical object with the same volume would be 7-23 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 20 km above the ground, with only fragmentary material reaching the Earth's surface.

2025 TC was first detected on 1 October 2025 (two days before its closest approach to the Earth), by the University of Hawaii's PANSTARRS telescope. The designation 2025 implies that it was the third asteroid (asteroid C - 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 C = 3) discovered in the first half of October 2025 (period 2025 T; the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

2025 TC is calculated to have a 1604 day (4.39 year) orbital period, with an elliptical orbit tilted at an angle of 1.92° to the plain of the Solar System which takes in to 0.80 AU from the Sun (80% of the average distance at which the Earth orbits the Sun) and out to 4.57 AU (4.57 times the distance at which the Earth orbits the Sun, more than three times the distance at which the planet Mars orbits). As an asteroid that is on average further from the Sun than the Earth, but which does get closer, 2025 is classified as an Apollo Group Asteroid.

The relative positions of 2025 TC and the planets of the Inner Solar System at 6.00 am on Friday 3 October 2025. JPL Small Body Database.

This means that 2025 TC has occasional close encounters with the Earth, with the last thought to have happened in September 1978 Venus, which it last cam close to in January 2008 and is next predicted to pass in June 2084, and Venus, which it last came close to in March 1967, Mars, which it last came close to in November 1955, and Jupiter, which it last came close to in July 2019.

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. In the case of 2025 TC, it is predicted that it will have another close encounter with Jupiter in October 2054, which will knock it onto an orbit which no longer comes close the planets of the Inner Solar System.

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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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