Celestia Forums

2024 YR4 is a NEO, Apollo-type asteroid, discovered on 2024-Dec-27. It was initially estimated to have a considerable chance of colliding with Earth in 2032-Dec-22 (1-in-32 on 2025-Feb-18), placing it at level 3 on the Torino scale for a few weeks. However, with subsequent observations, the risk of...

An update for C/2024 G3 was posted to the original post above. The comet disintegrated a few days after perihelion.

This addon adds the target asteroids of the NASA's Lucy mission. Launched 2021-Oct-16, Lucy will flyby 2 main-belt asteroids and 6 Jupiter trojans during its 12-year mission. The trojans are located at Jupiter's L4 and L5 points, orbiting in front or behind the planet. They are targets of interest g...

C/2024 G3 (ATLAS) is a long-period comet discovered in 2024-Apr-5. It reached perihelion on 2025-Jan-13, when it reached an apparent magnitude of -3.8, probably being the Great Comet of 2025. However, it began to disintegrate during the second half of Jan-2025. NOTE: To see the comet, you need to s...

This addon adds the seven target main-belt asteroids of the planned UAE's MBR Explorer mission. Scheduled to launch in March 2028, MBR Explorer will flyby over six asteroids between 2030 and 2033, with a rendezvous with 269 Justitia in 2034, in addition to deploying a Justitia lander. The presence o...

99942 Apophis is a NEO/PHA discovered in 2004-Jun-19. Initially estimated to have a 2.7% chance of impacting Earth in 2029, subsequent refinement of its orbit ruled out any possibility of impact within the next 100 years. On 2029-Apr-13, Apophis will safely pass within 31,700 km of the Earth's surf...

An update for C/2024 S1 was posted to the original post above. The comet disintegrated just before perihelion. Furthermore, he was not hyperbolic (until then, the data were preliminary and the observation arc very short).

C/2024 S1 (ATLAS) was a sungrazer and probable Kreutz comet discovered on 2024-Sep-27. It was predicted to reach perihelion in 2024-Oct-28, and if it survived the Sun's intense heat, it could potentially become visible to the naked eye during the day, with magnitude estimated to be between -5 and -...

C/2024 L5 (ATLAS) is a comet discovered on 2024-Jun-14 by the Asteroid Terrestrial-impact Last Alert System (ATLAS). What makes this comet stand out is a close encounter with Saturn on 2022-Jan-24, which placed it on a escape trajectory (hiperbolic) from Solar System. Before this encounter, its orb...

The Solar Dynamics Observatory (SDO) is a NASA solar observatory, launched in 2010-Feb-11, and operated in an inclined geosynchronous orbit. It continuously observes the Sun at different wavelengths. Remains operational in 2024. This is an update to the old addon made by BrianJ on Motherlode: - More...

In 2024-Sep-11, these two main-belt asteroids passed within about 300 km of each other (although there is considerable positional uncertainty for 2014 HO64). In any case, this close encounter could help determine the masses of these two asteroids. NOTES: - The closest approach occurs in 2024-Sep-11 ...

Juno add-on update. The accuracy of its XYZV trajectory has been improved after the year 2024, including so that several distant flybys of Io are simulated. And also all orbital phases were combined into a single XYZV file, during the period 2016-2025. Original add-on by toutatis NOTE: Install the ...

Below are the tables (in txt file) with updated flyby distances:

General XYZV update of the Galilean satellites . Until then, only incidental collisions had been corrected, but other flybys had not. Celestia's default VSOP87 makes virtually no flyby of the Jovian orbiters truly accurate, where it most often results in a flyby whose distance or relative position i...

TESS add-on update, with XYZV trajectory until 2026-Feb-07. A link to Wikipedia has also been added.

Original add-on by toutatis

54598 Bienor is a centaur that grazes the orbit of Uranus, discovered on 2000-Aug-27. Stellar occultations observed between 2022 and 2023 revealed that Bienor shape is highly elongated, as explained in this article.

Thanks to N3cronium for helping me determine the ascending node!

.....

.....

.....

12P/Pons-Brooks is a periodic Halley-type comet, with an orbital period of approximately 71 years. Pons-Brooks will reach perihelion in 2024-Apr-21, with closest approach to Earth (1.55 AU) in 2024-Jun-02. Given that the comet has already been observed by several amateur astronomers, I felt the nee...