2025 GN1

2025 GN1
2025 GN1 imaged by Cerro Tololo Observatory's Dark Energy Camera on 4 April 2025
Discovery
Discovered byCerro Tololo-DECam
Discovery siteCerro Tololo Obs.
Discovery date4 April 2025
Designations
2025 GN1
JKt019
Atira · NEO
Orbital characteristics
Epoch 21 November 2025 (JD 2461000.5)
Uncertainty parameter 4
Observation arc0.24 yr (88 days)
Aphelion0.7877 AU
Perihelion0.1362 AU
0.4620 AU
Eccentricity0.7116
0.314 yr (114.7 days)
199.148°
3° 8m 20.338s / day
Inclination32.835°
41.017°
6.106°
Earth MOID0.225 AU
Mercury MOID0.124 AU
Venus MOID0.027 AU
Physical characteristics
0.4±0.2 km
0.098±0.081 (assumed for X-type asteroids)
X
20.06±0.25

2025 GN1 is an Atira-type near-Earth asteroid discovered by the Dark Energy Camera (DECam) at Cerro Tololo Inter-American Observatory on 4 April 2025. With a diameter of 0.4 km (0.25 mi), it is believed to be a fragment of the near-Earth asteroid 2021 PH27, the closest orbiting asteroid to the Sun known as of 2026. 2025 GN1 and 2021 PH27 form an asteroid pair because they share identical orbits and spectral types, which suggest that they split apart from a single parent body over 10,500 years ago. The splitting of the parent body was likely caused by either thermal fracturing or rotational fissioning due to either outgassing or the YORP effect.