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Asteroid Near-Earth

2024 TK21

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(2024 TK21)

Where is it now

Distance from Sun
0.662 AU
True anomaly
19.47°
Distance from Earth
1.584 AU
As of
19 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 — 0.996 AU from the Sun Earth 2024 TK21 — 0.662 AU from the Sun 2024 TK21
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2024 TK21 is 1.584 AU from Earth today (13.2 light-minutes).

In the sky

Right ascension
14h 35m 59s
Declination
-10° 27′ 48″
Constellation
Libra
Distance from Earth
1.58 AU
Elongation from the Sun
14.04° — too close to the Sun to observe

Visible from both hemispheres.

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
0.838 AU
Eccentricity
0.2186
Inclination
16.42°
Orbital period
280.3 days
Perihelion
0.655 AU
Aphelion
1.021 AU
Longitude of ascending node
199.51°
Argument of periapsis
22.18°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 0.8 LD
0.0021 AU
Tisserand (Jupiter)
6.959

Orbit quality

Orbit poorly determined (uncertainty code 7).

Observations used
20
Data arc
2 days
First observed
14 October 2024
Last observed
16 October 2024
Residual RMS
0.61 ″
Solution · Otto Matic
16 October 2024

Visual & observation

Absolute magnitude (H)
25.14

Discovery & classification

Aten Near-Earth Object

Close approaches 53 on record

Flyby geometry
Ecliptic flyby of 2024 TK21 at 2027-10-16 20:48 UTC Top-down view of the ecliptic, Earth at the centre, for the 2027-10-16 20:48 UTC close approach of 2024 TK21. Catalogue miss distance 155.9 LD · 5.99 × 10⁷ km. The curve is the geocentric path from 2027-10-13 to 2027-10-19, 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 155.9 LD · 5.99 × 10⁷ km 2027-10-16 20:48 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2027-10-16 20:48 UTC close approach of 2024 TK21. Catalogue miss distance 155.9 LD · 5.99 × 10⁷ km. The curve is the geocentric path from 2027-10-13 to 2027-10-19, 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
2027-10-16 20:48:00 Earth 0.4006 AU 155.9 LD 19 km/s
2028-04-09 16:32:00 Earth 0.3387 AU 131.8 LD 14.3 km/s
2031-05-31 17:04:00 Earth 0.3895 AU 151.6 LD 12.8 km/s
2031-11-18 06:43:00 Earth 0.4674 AU 181.9 LD 17.5 km/s
2034-10-21 16:18:00 Earth 0.1275 AU 49.6 LD 8.9 km/s
2037-10-12 14:21:00 Earth 0.2535 AU 98.7 LD 14.8 km/s
2038-03-22 12:19:00 Earth 0.3209 AU 124.9 LD 13.4 km/s
2041-05-11 01:53:00 Earth 0.3741 AU 145.6 LD 14.2 km/s
2044-11-06 09:35:00 Earth 0.2583 AU 100.5 LD 10.7 km/s
2047-10-11 12:32:00 Earth 0.0992 AU 38.6 LD 11 km/s

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

Sources