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2024 YR4

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2024 YR4
2024 YR4 (centered) as tracked by the Very Large Telescope in January 2025
Discovery[1][2]
Discovered byATLAS–CHL (W68)
Discovery siteRio Hurtado, Chile
Discovery date27 December 2024
Designations
2024 YR4
Orbital characteristics[3] (JPL)
Epoch 5 May 2025 (JD 2460800.5)
Uncertainty parameter 4
Observation arc55 days
Earliest precovery date25 December 2024
Aphelion4.180 AU
Perihelion0.8515 AU
2.5159 AU
Eccentricity0.6616
3.991 yr
(1457.62 days)
40.40°
0.2470° per day
Inclination3.408°
271.366°
22 November 2024 (UTC)
19 November 2028 (UTC)[4]
21 November 2032 (UTC)[5]
134.361°
Earth MOID0.00283 AU (423,000 km; 1.10 LD)
Jupiter MOID1.2715 AU
Physical characteristics
  • 40–90 m (130–300 ft)
  • (est. pV = 0.05–0.25)[6]
  • 55 m (180 ft)
  • (est. pV = 0.154)[7]
  • 35–75 m (110–250 ft)
  • (est. pV = 0.1–0.3)[8]
0.32440 ± 0.00002 h (19.4640 ± 0.0012 min)[9]
S (most likely), L, or K[10][8]
24 (13 February)[11]
25 (26 February)
29.4 (2026 opposition)[12]
24.05±0.15 (phase corrected)[8]
23.96±0.28 (JPL)[3]

2024 YR4 is an asteroid estimated to be 40 to 90 metres (130 to 300 ft) in diameter that is classified as an Apollo-type (Earth-crossing) near-Earth object. As of 18 February 2025, 2024 YR4 was rated as a 3 on the Torino scale, with a 1-in-32 (3.1%) chance of impacting Earth on 22 December 2032.[7] NASA assigns a Palermo scale rating of −0.18 to 2024 YR4, corresponding to an impact hazard 66.1% of the background level.[7] The uncertainty region for the 2032 asteroid passage is 1.3 million km wide at the time of the Virtual Impactor.[13] It was discovered by the Chilean station of the Asteroid Terrestrial-impact Last Alert System (ATLAS) on 27 December 2024.[2][1] The discovery triggered the first step in planetary defense responses, prompting several major telescopes to gather data about the object and leading United Nations-endorsed space agencies to begin planning asteroid threat mitigation.[14][15][16]

The asteroid made a close approach of 828,800 kilometres (515,000 miles; 2.156 lunar distances) to Earth on 25 December 2024 (two days before its discovery) and is now moving away. Its next close approach is expected around 17 December 2028.[3] From early April 2025 until June 2028, 2024 YR4 will be too distant for ground-based telescopes to observe. However, space-based infrared telescopes could continue monitoring it during some of this period.[16][17] For example, the James Webb Space Telescope is scheduled to observe the asteroid between March and May 2025.[18] Preliminary analysis of spectra and photometric time series suggests the asteroid is a stony S-type (most likely), L-type asteroid, or K-type asteroid with a rotation period of approximately 19.5 minutes.[8] A number of known asteroids, some of them virtual impactors, follow orbits somewhat consistent with that of 2024 YR4.[19]

Provisional designation

[edit]

The asteroid's minor planet provisional designation 2024 YR4 was given by the Minor Planet Center when its discovery was announced on 27 December 2024.[2] "2024" indicates the year of the asteroid's discovery and the first letter "Y" indicates it was discovered during the second half-month of December in that year.[20] The "R4" indicates that it was the 117th provisional designation assigned in that half-month.[20]

Physical characteristics

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Size and mass

[edit]
Diameter comparison of 2024 YR4 and other notable meteoroids, with a Boeing 747 shown for scale

The diameter of 2024 YR4 has not been measured, but it can be estimated from its brightness (absolute magnitude) using a range of plausible values for its surface reflectivity (geometric albedo).[7][21] If 2024 YR4 reflects between 5% and 25% of visible light, then its diameter is between 40 and 90 m (130 and 300 ft).[6] NASA estimates a diameter of 55 m (180 ft) for an assumed geometric albedo of 0.154.[7] These estimates make 2024 YR4 around the same size as the asteroid that caused the 1908 Tunguska event or the iron–nickel asteroid that created the Meteor Crater in Arizona 50,000 years ago.[21] 2024 YR4 is significantly smaller than Dimorphos, the impact target of NASA's Double Asteroid Redirection Test (DART). The diameter and albedo of 2024 YR4 can be further constrained with thermal infrared observations, radar observations, an occultation of a star, or direct imaging by a spacecraft.[17]

The mass and density of 2024 YR4 have not been measured, but the mass can be loosely estimated with an assumed density and the estimated diameter. Assuming a density of 2.6 g/cm3,[22] which is within the density range for stony asteroids such as 243 Ida,[23] the Sentry risk table estimates a mass of 2.2×108 kg with an assumed diameter of 55 meters.[7]

Composition and rotation period

[edit]

Preliminary spectroscopic analysis from the Gran Telescopio Canarias and Lowell Discovery Telescope suggests that 2024 YR4 is either an S-type (17% of the asteroid population), L-type asteroid, or K-type asteroid, all of which point to a stony composition.[10][8][a]

Photometric observations by the Very Large Telescope (VLT) and the La Silla Observatory's 1.54-meter telescope indicate 2024 YR4 has a rotation period near 19.5 minutes.[10][9] This is a relatively fast rotation period for an asteroid, although it is not fast enough to rule out a rubble pile structure for 2024 YR4.[8] The brightness of 2024 YR4 varies by 0.42 magnitudes as it rotates, indicating it has an elongated shape with its longest equatorial length being at least 1.4 times that of its shortest equatorial length.[9][8] The VLT has also observed 2024 YR4 at multiple phase angles from 5° to 35°, which would allow for the construction of a phase curve which can constrain the asteroid's surface properties.[10]

Orbit

[edit]
Orbit diagram of 2024 YR4

2024 YR4 orbits the Sun on an elliptical orbit that crosses Earth's orbit, making it an Apollo-type near-Earth object.[3] The asteroid has an orbital period of about 3.99 years and an orbital inclination of 3.41 degrees with respect to Earth's orbit (ecliptic).[3] Astronomers Carlos and Raúl de la Fuente Marcos have proposed that 2024 YR4 could be related to a group of near-Earth asteroids on similar orbits, including the 2015 Porangaba meteor whose orbit has a 5% probability of matching that of 2024 YR4.[19]

The asteroid came to perihelion (closest approach to the Sun) on 22 November 2024. The asteroid made a close approach to Earth on 25 December 2024, two days before its discovery. During this encounter, the asteroid passed 828,800 km (515,000 mi; 2.156 LD) from Earth and then 488,300 km (303,400 mi; 1.270 LD) from the Moon.[3] The asteroid will make its next close approach to Earth around 17 December 2028, when it will pass 7,931,000 ± 327,000 km (4,928,000 ± 203,000 mi; 20.63 ± 0.85 LD) from the planet.[3] The 2028 encounter will provide astronomers the opportunity to perform additional observations and extend the observation arc by four years. This will greatly improve calculations of 2024 YR4's orbit in preparation for its close approach around 22 December 2032.[24] Since the close approach of 2032 is not constrained well enough to rule out an Earth impact in 2032, the resulting perturbations by the Earth–Moon system are not well constrained, and close approaches after 2032 are not well constrained. By 2035, the uncertainty in the asteroid's position will be greater than 1 AU, the distance between Earth and the Sun (150 million km).[25]

2032 potential impact

[edit]
Animation of 2024 YR4 orbiting around the Sun, showing the 2032 predicted approach
  2024 YR4 ·   Sun ·   Mercury ·   Venus ·   Earth ·   Mars

Calculations using the observation arc of 55 days as of 18 February 2025 find that 2024 YR4 has a 1-in-32 (3.1%) chance of impacting Earth on 22 December 2032 around 14:02 UT[7] and a smaller possibility of impacting the Moon about an hour later around 15:19 UT. The nominal closest approach to Earth is on the 22nd at 11:37 UT (with an uncertainty in the closest approach time of about 9.5 hours and being 2.5 hours earlier than virtual impactor) at a distance of 123,000 kilometres (76,000 miles; 0.32 lunar distances), with a 3-sigma uncertainty of 458,000 kilometres (285,000 miles; 1.19 lunar distances). The nominal closest approach to Moon is six hours later at 17:44 UT[3] Due to 2024 YR4's size and greater-than-1% impact probability, it is rated at Torino scale level 3, which has prompted the International Asteroid Warning Network to issue a notice on 29 January 2025.[16][26] This is the second-highest Torino scale rating an asteroid has ever reached, behind 99942 Apophis which briefly ranked Torino scale level 4 in late 2004.[26] NASA gives a Palermo scale rating of −0.18 for 2024 YR4, which corresponds to an impact hazard of 66.1% of the background hazard level.[7] The European Space Agency gives a Palermo scale rating of −0.20 with an impact probability of 2.81%,[6] while NEODyS gives −0.21 with an impact probability of 2.27%.[27]

JPL #57 nominal distance for the 22 December 2032 14:02 UT Virtual Impactor Scenario
JPL Horizons
nominal geocentric
distance (AU) 		uncertainty
region
(3-sigma)
0.0011 AU (160,000 km; 0.43 LD)[13] ± 641 thousand km[13][b]
Evolution of nominal close approach estimates for 22 December 2032
Solution Observation
arc
(in days) 		JPL Horizons
nominal geocentric
distance (AU) 		uncertainty
region
(3-sigma) 		Impact
probability 		Torino
scale 		Palermo
scale
(max)

2024 Dec 30

2 (53 obs) 1:1040 (0.096%) 1 −1.73

2024 Dec 31

3 (71 obs) 1:920 (0.11%) 1 −1.66

2025 Jan 1

4 (87 obs) 1:870 (0.11%) 1 −1.64

2025 Jan 2

6 (109 obs) 1:842 (0.12%) 1 −1.63

2025 Jan 3

7 (120 obs) 1:760 (0.13%) 1 −1.61
JPL #14

2025 Jan 6

8 (145 obs) 0.01706 AU (2.552 million km; 6.64 LD) ± 9.62 million km 1:730 (0.14%) 1
JPL #15

2025 Jan 6

11 (158 obs) 0.01537 AU (2.299 million km; 5.98 LD) ± 9.55 million km 1:710 (0.14%) 1 −1.53

2025 Jan 11

14 (170 obs) 1:630 (0.16%) 1 −1.53
JPL #27

2025 Jan 20

26 (198 obs) 1:320 (0.31%) 1
JPL #30

2025 Jan 22

28 (213 obs) 0.00068 AU (102,000 km; 0.26 LD)[c] ± 3.37 million km 1:190 (0.52%) 1 −0.93
JPL #32

2025 Jan 23

29 (219 obs) 0.00171 AU (256,000 km; 0.67 LD)[d] ± 2.28 million km 1:110 (0.91%) 1 −0.69
JPL #34

2025 Jan 24

30 (227 obs) 0.00113 AU (169,000 km; 0.44 LD) ± 1.96 million km 1:110 (0.91%) 1 −0.69
JPL #35

2025 Jan 27

33 (238 obs) 0.00004564 AU (6,829 km; 0.01776 LD)[e] ± 1.605 million km 1:83 (1.2%) 3 −0.57
JPL #36

2025 Jan 28

34 (245 obs) 0.00071 AU (106,000 km; 0.28 LD) ± 1.55 million km 1:83 (1.2%) 3[7] −0.56
JPL #37

2025 Jan 29

35 (257 obs) 0.00085 AU (127,000 km; 0.33 LD) ± 1.408 million km 1:77 (1.3%) 3 −0.53
JPL #39

2025 Jan 30

36 (261 obs) 0.00087 AU (130,000 km; 0.34 LD) ± 1.408 million km 1:77 (1.3%) 3 −0.53
JPL #40

2025 Jan 31

37 (276 obs) 0.00046 AU (69,000 km; 0.18 LD) ± 1.2 million km 1:63 (1.6%) 3 −0.47
JPL #41

2025 Feb 1

38 (284 obs) 0.00037 AU (55,000 km; 0.14 LD) ± 1.119 million km 1:59 (1.7%) 3 −0.43
JPL #42

2025 Feb 2

39 (289 obs) 0.00185 AU (277,000 km; 0.72 LD) ± 1.049 million km 1:71 (1.4%) 3 −0.52
JPL #43

2025 Feb 3

40 (292 obs) 0.00165 AU (247,000 km; 0.64 LD) ± 998,000 km 1:67 (1.5%) 3 −0.49
JPL #44

2025 Feb 4

41 (294 obs) 0.00151 AU (226,000 km; 0.59 LD) ± 981,000 km 1:63 (1.6%) 3 −0.46
JPL #45

2025 Feb 5

42 (307 obs) 0.00116 AU (174,000 km; 0.45 LD) ± 892,000 km 1:53 (1.9%) 3 −0.40
JPL #46

2025 Feb 6

43 (315 obs) 0.00059 AU (88,000 km; 0.23 LD) ± 819,000 km 1:43 (2.3%) 3 −0.31
JPL #47

2025 Feb 7

43 (325 obs) 0.00080 AU (120,000 km; 0.31 LD) ± 792,000 km 1:45 (2.2%) 3 −0.32
JPL #48

2025 Feb 8

44 (336 obs) 0.00061 AU (91,000 km; 0.24 LD) ± 764,000 km 1:42 (2.4%) 3 −0.29
JPL #49

2025 Feb 9

45 (343 obs) 0.00105 AU (157,000 km; 0.41 LD) ± 739,000 km 1:45 (2.2%) 3 −0.34
JPL #50

2025 Feb 10

45 (347 obs) 0.00112 AU (168,000 km; 0.44 LD)[f] ± 712,000 km 1:48 (2.1%) 3 −0.34
JPL #51

2025 Feb 12

45 (348 obs) 0.00114 AU (171,000 km; 0.44 LD)[f] ± 712,000 km 1:48 (2.1%) 3 −0.35
JPL #53

2025 Feb 13

45 (346 obs) 0.00112 AU (168,000 km; 0.44 LD)[f] ± 712,000 km 1:48 (2.1%) 3 −0.34
JPL #54

2025 Feb 14

45 (354 obs) 0.00105 AU (157,000 km; 0.41 LD)[f] ± 707,000 km 1:45 (2.2%) 3 −0.33
JPL #55

2025 Feb 15

45 (363 obs) 0.00105 AU (157,000 km; 0.41 LD)[f] ± 707,000 km 1:45 (2.2%) 3 −0.33
JPL #56

2025 Feb 17

54 (368 obs) 0.00099 AU (148,000 km; 0.39 LD) ± 481,000 km 1:38 (2.6%) 3 −0.25
JPL #57

2025 Feb 18

55 (370 obs) 0.00082 AU (123,000 km; 0.32 LD) ± 458,000 km 1:32 (3.1%) 3 −0.18

Impact effect

[edit]
Impact risk corridor for the 2032 approach[24][16]

The risk corridor of 2024 YR4's possible impact locations runs from the eastern equatorial Pacific Ocean to Northern South America, the equatorial Atlantic Ocean, Nigeria, central Africa, the north of east Africa, the southwest corner of the Arabian peninsula, the Northwestern Indian Ocean, India, and ends in Bangladesh.[24][16] Using NASA's estimated diameter, mass, and density for 2024 YR4, the asteroid would release energy equivalent to 7.8 megatonnes of TNT (32.6 PJ) if it were to impact Earth at its predicted velocity at atmosphere entry of 17.32 km/s (10.76 mi/s),[7] equivalent to about 367 of the "Fat Man" bomb dropped on Nagasaki, 2 and a half of Grapple Y, 51% of Castle Bravo, or 15.4% of Tsar Bomba. Due to its stony composition, this would more likely produce a meteor air burst than an impact crater (for an impact on a continent) or tsunami (for an oceanic impact). It could cause damage as far as 50 km (30 mi) from the impact site.[21][26] Despite its potential to cause damage if it were to impact, 2024 YR4 is not categorized as a potentially hazardous object (PHO) because it has an absolute magnitude dimmer than 22, which usually means that such an asteroid is less than 140 m (460 ft) in diameter and its potential damage therefore would be localized.[28]

Possible impact on the Moon

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According to David Rankin, an operations engineer for the University of Arizona's Catalina Sky Survey, 2024 YR4 also has a 0.3% probability of impacting the Moon on 22 December 2032[29] around 15:17–15:21 UT.[30] An impact before 15:18 would be visible in the shaded part of the waning gibbous moon. The effects of the collision could create an impact crater 500 to 2,000 meters wide on the lunar surface, releasing about 5.2 megatonnes of TNT (21.8 PJ) of energy if it were to impact the Moon at a velocity estimated to be 13.89 km/s (8.63 mi/s), an explosion 343 times more powerful than the atomic bomb dropped on Hiroshima. The potential impact zone extends from just south of Mare Crisium, a solidified lava plain, to Tycho, an ancient crater, all located on the visible side of the Moon.

Michael Busch of the SETI Institute, notes that an explosion on the Moon "would be very obvious to any spacecraft observing from lunar orbit" but may not be as visible to the unaided eye from Earth due to the Moon's brightness. However, other astronomers believe the impact could be visible from Earth. Gareth Collins suggested that "the impact flash of vaporized rock would be visible from Earth, even in the daytime", while Daniel Bamberger of the Northolt Branch Observatories in London stated that the impact "could be brighter than the full moon" making it clearly visible to the naked eye. [29][31]

Observation opportunities

[edit]

2025

[edit]

Additional observations of 2024 YR4 are necessary to reduce uncertainties in its trajectory and determine whether it will impact Earth.[16] Because the asteroid is now moving away from Earth, it is becoming fainter, necessitating the use of larger aperture telescopes such as the 10-meter Keck telescope and the Very Large Telescope.[17] The asteroid was not observed between 9–15 February and 11-13 January 2025[1] due to interference from moonlight. After mid-February, a 2-meter telescope or better is required. After 4 March 2025, a 4-meter or better class telescope will be required. After 1 April, an 8-meter or better will be required. Space-based infrared telescopes such as the James Webb Space Telescope (JWST) will be able to observe 2024 YR4 at farther distances until 20 May.[32][17] The JWST is scheduled to observe 2024 YR4 between 1 and 24 March, when the position of the asteroid first becomes compatible with the pointing restrictions of the telescope, and again between 20 April and 20 May 2025. JWST will use its NIRCam and Mid-Infrared Instrument, which will provide measurements of both 2024 YR4's position and its infrared thermal emission, from the latter of which the asteroid's size and albedo can be better estimated.[33][18]

Precovery

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The orbital uncertainty of 2024 YR4 may be further reduced with precovery observations, in which the asteroid would be detected in archival telescope images taken before its discovery. The earliest known precovery observation of 2024 YR4 was by ATLAS on 25 December 2024, but this is just two days before its discovery and the measured position of the asteroid in that observation is also more uncertain than in later observations, due to the rapid motion of the asteroid and a longer exposure than would have been optimal for observations of such a fast-moving asteroid.[34][g] The asteroid passed within 12 million km of Earth in September 2016 and within 20 million km of Earth in October 2020.[3] A search through 2016 Subaru Telescope archival images of a region, where 2024 YR4 might have been, did not find it.[24] According to Sam Deen,[36] including this negative precovery data in the orbit calculation decreases the likelihood that the asteroid is somewhere along 60–80% of the non-impacting trajectories calculated from the observation arc to late January, which he estimated raised 2024 YR4's impact probability to 3% at that time; also including the single poorer-quality 25 December 2024 precovery observation increased the probability to 6%.[34] Deen said "I invite people to double check me because it's been just me looking at this. I could have missed something." Images of the region taken in 2016 by Palomar Observatory, not made public as of January 2025, may provide further information.[24]

Astronomers of the Catalina Sky Survey have inspected a set of images from Mount Lemmon Survey, including images containing the virtual impactor's predicted location; however, no candidates were found.[32] Astronomers of the Pan-STARRS survey identified a few images in 2012, 2016 and 2020, again with no candidates found, alongside images from 2012 and 2020 which did not have a sufficiently deep limiting magnitude to detect any faint objects. Paolo Tanga checked for possible detections by the Gaia spacecraft, but concluded that 2024 YR4 never came within the spacecraft's field of view. James Bauer checked the NEOWISE data, Deborah Woods checked Space Surveillance Telescope data, and Julien de Wit searched data from TESS and other exoplanet surveys; none of these searches found detections of 2024 YR4.[32]

Stellar occultation

[edit]

A positive occultation detection would make possible measurements of the size and shape of the asteroid and more precise measurements of its position. As of 11 February 2025, no positive stellar occultation has been reported.[37] A 6 February occultation had its path very close to the Connecticut–Rhode Island border, and no occultation results have been reported so far. An 8 February occultation passed Xiamen, GuoGhenyang and two negative occultations were reported.[38] The uncertainty range for the path of both occultations on Earth was a few kilometers wide, and while Fresnel diffraction broadens the penumbral to slightly more than twice the diameter of the asteroid—to 100 and 140 m (330 and 460 ft)—an uncertainty of a few kilometers is still too wide compared to this penumbra to efficiently place movable observing stations on the path.[37]

2028

[edit]

Observations of the asteroid when it passes near Earth again in 2028 will enable the calculation of a very precise orbit and a much refined estimation of the impact likelihood in 2032 as it will extend the observation arc by four years. The asteroid will be too faint for observation until June 2028.[16] It will be about magnitude 25 when it comes to opposition around 19 July 2028 at an Earth distance of 0.78 AU (117 million km) but it will continue to get closer until December 17 when it will be 20 lunar distances away.[3] If the 2028 observations do not rule out a 2032 impact, then an asteroid redirect mission similar to DART could be sent to 2024 YR4 to avert its impact.[39]

See also

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Notes

[edit]
  1. ^ C-type asteroids are about 75% of the asteroid population, S-type asteroids are about 17%, and M-type asteroids (iron–nickel) are about 5%.
  2. ^ The uncertainty region is larger at the 14:02 UT Virtual Impactor Scenario because it is 2.5 hours after the nominal (best-fit) Earth approach.
  3. ^ JPL #30 with a 28-day observation arc had an uncertainty of almost ± 3 days for the Earth close approach date in 2032.[3]
  4. ^ JPL #32 The nominal orbit is 1,129 km from the Moon, which is less than the Moon's radius of 1,737.
  5. ^ JPL #35: The nominal 14:17 UT Earth approach is 6829 km (1.07 R🜨) and Earth has a radius of 6378 km. This is the nearest nominal orbit in the JPL Small-Body Database record.
  6. ^ a b c d e 2024 YR4 could not be observed at that time because of proximity to the full moon
  7. ^ The 25 December 2024 observation has a high RMS of 1.6 arcseconds in right ascension and 0.7 arcseconds in declination.[35]

References

[edit]
  1. ^ a b c "2024 YR4". Minor Planet Center. Archived from the original on 17 February 2025. Retrieved 17 February 2025.
  2. ^ a b c Minor Planet Center Staff (27 December 2024). "MPEC 2024-Y140 : 2024 YR4". Minor Planet Electronic Circular. 2024-Y140. Minor Planet Center. Bibcode:2024MPEC....Y..140W. doi:10.48377/MPEC/2024-Y140. Retrieved 27 January 2025.
  3. ^ a b c d e f g h i j k "JPL Small-Body Database Lookup: (2024 YR4)" (2025-02-17 last obs.). Jet Propulsion Laboratory. Archived from the original on 22 January 2025. Retrieved 17 February 2025.(See archive for JPL #30 solution)
  4. ^ "2028 Perihelion" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Archived from the original on 2 February 2025. Retrieved 1 February 2025.
  5. ^ "2032 Perihelion" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. 7 February 2025. Retrieved 7 February 2025.
  6. ^ a b c "2024YR4". Near-Earth Objects Coordination Centre. European Space Agency. 18 February 2025. Retrieved 18 February 2025.
  7. ^ a b c d e f g h i j "(2024 YR4) – Earth Impact Risk Summary". Center for Near-Earth Object Studies. NASA. 17 February 2025. Archived from the original on 28 January 2025. Retrieved 17 February 2025.
  8. ^ a b c d e f g Devogèle, Maxime; DeLeon, Julia; Dotto, Elisabetta; Hainaut, Olivier; Ieva, Simone; Moskovitz, Nick; et al. (15 February 2025). "Physical characterization of 2024 YR4" (PDF). International Asteroid Warning Network. Retrieved 15 February 2025.
  9. ^ a b c Pravec, Petr. "'Prepublished' periods of asteroids". Ondrejov Asteroid Photometry Project. Astronomical Institute of the Czech Academy of Sciences. Archived from the original on 30 January 2025. Retrieved 29 January 2025.
  10. ^ a b c d "2024 YR4". International Asteroid Warning Network. 29 January 2025. Archived from the original on 30 January 2025. Retrieved 29 January 2025.
  11. ^ "Visual Magnitude". JPL Horizons. Retrieved 13 February 2025.
  12. ^ "2026 Opposition" (Maximum solar elongation is 176 degrees). JPL Horizons. Retrieved 9 February 2025.
  13. ^ a b c "JPL Horizons: 2024 YR4 geocentric distance and uncertainty at Virtual Impactor time of 22 Dec 2032 14:02 UT". JPL Horizons. Archived from the original on 5 February 2025. Retrieved 18 February 2025. (Uncertainty of ± 641435km, making the uncertainty region 1.3 million km wide.)
  14. ^ Sample, Ian (30 January 2025). "Asteroid triggers global defence plan amid chance of collision with Earth in 2032". The Guardian. Retrieved 30 January 2025.
  15. ^ Andrews, Robin George (29 January 2025). "Astronomers Are Keeping an Eye on This Asteroid's Odds of Hitting Earth". The New York Times. Archived from the original on 30 January 2025. Retrieved 30 January 2025.
  16. ^ a b c d e f g "International Asteroid Warning Network (IAWN) Potential Asteroid Impact Notification" (PDF). International Asteroid Warning Network. 29 January 2025. Archived (PDF) from the original on 30 January 2025. Retrieved 29 January 2025.
  17. ^ a b c d "Asteroid 2024 YR4 reaches level 3 on the Torino Scale". Center for Near-Earth Object Studies. NASA. 31 January 2025. Retrieved 1 February 2025.
  18. ^ a b Rivkin, Andrew S.; et al. (5 February 2025). "Size Measurements of a Potential Earth-Impacting Asteroid with JWST MIRI and NIRCAM". JWST Proposal (9239). Space Telescope Science Institute. Retrieved 5 February 2025.
  19. ^ a b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (18 February 2025). "Is Virtual Impactor 2024 YR4 Related to the Porangaba Meteorite Fall?". Research Notes of the AAS. 9 (2). Bibcode:2025RNAAS...9...41D. doi:10.3847/2515-5172/adb60e. 41.
  20. ^ a b "New- And Old-Style Minor Planet Designations". Minor Planet Center. Retrieved 9 February 2025.
  21. ^ a b c Lea, Robert (28 January 2025). "Astronomers discover 196-foot asteroid with 1-in-83 chance of hitting Earth in 2032". Space.com. Archived from the original on 28 January 2025. Retrieved 28 January 2025.
  22. ^ "Sentry API Version 2.0". Jet Propulsion Laboratory. NASA. July 2021. Archived from the original on 28 October 2021. Retrieved 9 February 2025. mass: This estimate assumes a uniform spherical body with the computed diameter and a mass density of 2.6 g/cm3. The mass estimate is somewhat more rough than the diameter estimate, but generally will be accurate to within a factor of three.
  23. ^ Belton, M. J. S.; Chapman, C. R.; Thomas, P. C.; Davies, M. E.; Greenberg, R.; Klaasen, K.; et al. (1995). "Bulk density of asteroid 243 Ida from the orbit of its satellite Dactyl". Nature. 374 (6525): 785–788. Bibcode:1995Natur.374..785B. doi:10.1038/374785a0. S2CID 4333634.
  24. ^ a b c d e Chandler, David L. (28 January 2025). "Newly Discovered Asteroid Has Slight Chance of Earth Impact in 2032". skyandtelescope.org. Retrieved 28 January 2025.
  25. ^ "2024 YR4 uncertainty (RNG_3sigma in km) in 2035". JPL Horizons. Archived from the original on 17 February 2025. Retrieved 17 February 2025.
  26. ^ a b c Whitt, Kelly Kizer (27 January 2025). "Asteroid 2024 YR4 has non-zero odds of hitting Earth". EarthSky. Archived from the original on 28 January 2025. Retrieved 27 January 2025.
  27. ^ "2024YR4 Impactor Table". NEODyS-2. University of Pisa. 18 February 2025. Retrieved 18 February 2025.
  28. ^ "NEO Basics – NEO Groups". Center for Near-Earth Object Studies. NASA. Retrieved 10 February 2025.
  29. ^ a b Dewan, Pandora. "'City-killer' asteroid 2024 YR4 could hit the moon instead of us, scientists say". Space.com. Retrieved 17 February 2025.
  30. ^ Gray, Bill. "Risk Corridor for Gibbous Moon". Find_Orb. Archived from the original on 10 February 2025. Retrieved 18 February 2025.
  31. ^ Andrews, Robin George. "There's a tiny chance the asteroid headed for Earth could hit the moon". NewScientist. Retrieved 17 February 2025.
  32. ^ a b c |title = 2024 YR4 Astrometry at IAWN |url = https://iawn.net/documents/20250204_20th_Vienna/ESA-S2P-PD-HO-0261_1_0_2024_YR4_Astrometry_at_IAWN.pdf |publisher = International Asteroid Warning Network |date = 15 February 2025 |access-date = 15 February 2025}}
  33. ^ Andrews, Robin George (5 February 2025). "This asteroid may hit Earth in 2032. Don't panic—scientists have a plan". National Geographic. Retrieved 5 February 2025.
  34. ^ a b Deen, Sam (27 January 2025). "2024 YR4: Torino scale 3, negative observations, 3–6% impact?". Minor Planets Mailing List. Retrieved 27 January 2025.
  35. ^ "2024YR4 Observational Details". NEODyS-2. University of Pisa. Retrieved 30 January 2025.
  36. ^ "Sam Deen, private investigator of Solar System bodies from California". Stefan Kürti's Astro Web. 20 May 2024. Archived from the original on 22 July 2024. Retrieved 30 January 2025.
  37. ^ a b Herald, Dave (31 January 2025). "Re: 2024 YR4 occultation on Feb 6 and later..." International Occultation Timing Association (IOTA) Mailing List. Retrieved 31 January 2025.
  38. ^ https://groups.io/g/IOTAoccultations/topic/111125999#msg81657
  39. ^ O'Callaghan, Jonathan (31 January 2025). "Newfound Asteroid May Hit Earth in 2032, Scientists Say". Scientific American. Archived from the original on 1 February 2025. Retrieved 1 February 2025.
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