Astro Corner
Your corner of the universe.
EN
Celestial object
C/2021 S1 (ATLAS)
2021 S1, ATLAS, C/2021 S1 (ATLAS)
Make this Object part of your astronomy journeyMembers can add targets, record observations, link images and watch this Object for visibility alerts.
Reference data
RADate-dependentMoving object · use an ephemeris
DecDate-dependentMoving object · use an ephemeris
Magnitude—
Angular size—
Position angle—
Distance—
Constellation—
Solar System catalogue
JPL SBDBMoving-object reference
Comets and minor planets move against the background sky. Astro Corner therefore keeps their orbital catalogue record separately and does not pretend a single RA/Dec is permanently correct.
Primary designation2021 S1
JPL SPK-ID1003813
Orbit classHYP
Orbit IDJPL 35
Near-Earth objectNo
Potentially hazardousNo
Epoch · JD2459661.5
Eccentricity1.000956489043
Semi-major axis-6397.577104410 AU
Perihelion distance6.119212400 AU
Orbital period—
Earth MOID5.224080000 AU
Jupiter Tisserand1.876000
Inclination52.08895857°
Absolute magnitude · H—
Comet total magnitude · M16.7000 · K1 10.0000
Diameter—
Albedo—
Last catalogue sync2026-09-18 12:40:02
Planning coordinates are intentionally separate.A later Horizons ephemeris layer can calculate the object's apparent position for a specific date, time and observing location. Until then, static-sky tools are hidden for this record rather than showing misleading coordinates.
Open JPL Small-Body Database 
Reference transparencySources & data provenanceSee where catalogue identities and imported reference fields came from.4 records
Community observations
No public community observations for this object yet.
Guides & knowledge
Published Guides that reference this canonical object.
No published Guides reference this object yet.
Images of this object
Confirmed manual or plate-solve links to this canonical object. Solver suggestions are excluded until confirmed by the image owner.
No visible confirmed images are linked to this object yet.