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Asteroid Near-Earth

2021 SJ88

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(2021 SJ88)

Where is it now

Distance from Sun
0.833 AU
True anomaly
146.75°
Distance from Earth
0.821 AU
As of
15 October 2026

Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.

Sun Earth — 0.997 AU from the Sun Earth 2021 SJ88 — 0.833 AU from the Sun 2021 SJ88
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 SJ88 is 0.821 AU from Earth today (6.8 light-minutes).

In the sky

Right ascension
17h 04m 19s
Declination
-17° 34′ 00″
Constellation
Ophiuchus
Distance from Earth
0.82 AU
Elongation from the Sun
53.81° — near the Sun — look low at dusk or dawn

Favours the southern hemisphere; low or below the horizon from far north.

From your location

See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.

Orbital elements

Semi-major axis
0.645 AU
Eccentricity
0.5606
Inclination
8.79°
Orbital period
189.2 days
Perihelion
0.283 AU
Aphelion
1.006 AU
Longitude of ascending node
186.35°
Argument of periapsis
356.78°
Epoch · J2000
2459486.5
Orbit class · ATE
Aten
Earth MOID · 1.0 LD
0.0026 AU
Tisserand (Jupiter)
8.644

Orbit quality

Orbit very uncertain — the object may be effectively lost (uncertainty code 8).

Observations used
5
First observed
29 September 2021
Last observed
29 September 2021
Residual RMS
0.1 ″
Solution · Otto Matic
10 January 2024

Visual & observation

Absolute magnitude (H)
30.92

Discovery & classification

Aten Near-Earth Object

Close approaches 100 on record

Flyby geometry
Ecliptic flyby of 2021 SJ88 at 2032-10-01 18:32 UTC Top-down view of the ecliptic, Earth at the centre, for the 2032-10-01 18:32 UTC close approach of 2021 SJ88. Catalogue miss distance 171.2 LD · 6.58 × 10⁷ km. The curve is the geocentric path from 2032-09-28 to 2032-10-04, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 171.2 LD · 6.58 × 10⁷ km 2032-10-01 18:32 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2032-10-01 18:32 UTC close approach of 2021 SJ88. Catalogue miss distance 171.2 LD · 6.58 × 10⁷ km. The curve is the geocentric path from 2032-09-28 to 2032-10-04, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate.

JPL Horizons

When (UTC) Body Distance Lunar distances Relative speed
2031-10-04 07:41:00 Venus 0.1083 AU 42.2 LD 24.5 km/s
2032-10-01 18:32:00 Earth 0.4398 AU 171.2 LD 26.1 km/s
2033-10-09 08:48:00 Earth 0.2387 AU 92.9 LD 18.7 km/s
2036-09-12 10:40:00 Earth 0.1724 AU 67.1 LD 16.3 km/s
2050-09-14 14:16:00 Earth 0.2519 AU 98.0 LD 19.4 km/s
2051-09-21 14:09:00 Earth 0.4406 AU 171.5 LD 26.4 km/s
2053-10-03 08:46:00 Venus 0.1181 AU 46.0 LD 20.3 km/s
2056-09-29 15:47:00 Mercury 0.0889 AU 34.6 LD 34.5 km/s
2056-09-29 15:47:00 Merc 0.0889 AU 34.6 LD 34.5 km/s
2058-03-20 06:10:00 Venus 0.0516 AU 20.1 LD 20.4 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources