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Asteroid Near-Earth

537829

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537829 (2015 XY378)

Where is it now

Distance from Sun
0.972 AU
True anomaly
204.78°
Distance from Earth
1.391 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 537829 — 0.972 AU from the Sun 537829
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 537829 is 1.391 AU from Earth today (11.6 light-minutes).

In the sky

Right ascension
10h 58m 54s
Declination
+16° 17′ 18″
Constellation
Leo
Distance from Earth
1.39 AU
Elongation from the Sun
44.31° — near the Sun — look low at dusk or dawn

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
0.71 AU
Eccentricity
0.4893
Inclination
13.92°
Orbital period
218.6 days
Perihelion
0.363 AU
Aphelion
1.058 AU
Longitude of ascending node
1.2°
Argument of periapsis
265.69°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 76.8 LD
0.1973 AU
Tisserand (Jupiter)
7.952

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
168
Data arc
10.04 years
First observed
1 December 2015
Last observed
16 December 2025
Residual RMS
0.44 ″
Solution · Otto Matic
24 May 2026

Physical properties

Mean radius
0.16 km

Visual & observation

Geometric albedo
0.214
Absolute magnitude (H)
19.51

Discovery & classification

Discovered by
WISE
Discovery date
12 December 2015
Discovery site
WISE

Also known as 2015 XY378

Aten Near-Earth Object

Close approaches 224 on record

When (UTC) Body Distance Lunar distances Relative speed
2029-05-08 08:25:00 Mercury 0.0866 AU 33.7 LD 21 km/s
2029-05-08 08:25:00 Merc 0.0866 AU 33.7 LD 21 km/s
2030-07-18 03:39:00 Merc 0.0649 AU 25.2 LD 27.4 km/s
2030-07-18 03:39:00 Mercury 0.0649 AU 25.2 LD 27.4 km/s
2031-09-28 15:25:00 Merc 0.0974 AU 37.9 LD 34.9 km/s
2031-09-28 15:25:00 Mercury 0.0974 AU 37.9 LD 34.9 km/s
2037-04-04 08:55:00 Venus 0.1041 AU 40.5 LD 19.8 km/s
2041-12-22 21:41:00 Merc 0.0844 AU 32.9 LD 36.6 km/s
2041-12-22 21:41:00 Mercury 0.0844 AU 32.9 LD 36.6 km/s
2043-03-05 09:29:00 Merc 0.0202 AU 7.9 LD 28.5 km/s

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

Sources