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Asteroid Near-Earth

2021 TB15

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(2021 TB15)

2021 TB15 is an asteroid in the Aten orbit class. Its orbit takes it from 0.75 AU to 1.22 AU from the Sun; one orbit takes 356.9 days. Orbit from the JPL solution of 20 October 2022.

Where is it now

Distance from Sun
1 AU
True anomaly
252.74°
Distance from Earth
0.53 AU
As of
2 November 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 — 0.992 AU from the Sun Earth 2021 TB15 — 1 AU from the Sun 2021 TB15
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2021 TB15 is 0.53 AU from Earth today (4.4 light-minutes).

In the sky

Right ascension
11h 25m 18s
Declination
+46° 54′ 07″
Constellation
Ursa Major
Distance from Earth
0.53 AU
Elongation from the Sun
75.06° — well clear of the Sun

Favours the northern hemisphere; low or below the horizon from far south.

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
0.985 AU
Eccentricity
0.2377
Inclination
29.51°
Orbital period
356.9 days
Perihelion
0.751 AU
Aphelion
1.219 AU
Longitude of ascending node
26.54°
Argument of periapsis
149.49°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 63.5 LD
0.1632 AU
Tisserand (Jupiter)
6.019

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
56
Data arc
2.98 years
First observed
29 October 2019
Last observed
20 October 2022
Residual RMS
0.67 ″
Solution · Otto Matic
20 October 2022

Visual & observation

Absolute magnitude (H)
23.32

Discovery & classification

Aten Near-Earth Object

Close approaches 143 on record

Flyby geometry
Ecliptic flyby of 2021 TB15 at 2058-06-01 14:29 UTC Sun 164.7 LD · 6.33 × 10⁷ km 2058-06-01 14:29 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2058-06-01 14:29 UTC close approach of 2021 TB15. Catalogue miss distance 164.7 LD · 6.33 × 10⁷ km. The curve is the geocentric path from 2058-05-29 to 2058-06-04, 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. At closest approach the object is south of the ecliptic. 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
2027-02-04 19:06:00 Venus 0.0729 AU 28.4 LD 17.4 km/s
2043-09-15 21:18:00 Venus 0.0675 AU 26.3 LD 17.4 km/s
2058-06-01 14:29:00 Earth 0.4232 AU 164.7 LD 21.1 km/s
2059-05-19 18:33:00 Earth 0.3339 AU 129.9 LD 19.9 km/s
2059-09-22 19:11:00 Earth 0.4888 AU 190.2 LD 15.5 km/s
2060-04-24 21:07:00 Venus 0.0949 AU 36.9 LD 17.4 km/s
2060-05-06 00:09:00 Earth 0.2635 AU 102.5 LD 19.1 km/s
2060-10-01 11:45:00 Earth 0.4144 AU 161.3 LD 15.3 km/s
2061-04-23 00:25:00 Earth 0.2301 AU 89.5 LD 18.7 km/s
2061-10-09 07:23:00 Earth 0.337 AU 131.2 LD 15.1 km/s

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

Sources