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Asteroid Near-Earth Potentially hazardous

2015 BL311

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(2015 BL311)

Where is it now

Distance from Sun
3.59 AU
True anomaly
163.76°
Distance from Earth
4.475 AU
As of
11 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.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.998 AU from the Sun Earth 2015 BL311 — 3.59 AU from the Sun 2015 BL311
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2015 BL311 is 4.475 AU from Earth today (37.2 light-minutes).

In the sky

Right ascension
11h 36m 31s
Declination
+01° 20′ 25″
Constellation
Leo
Distance from Earth
4.47 AU
Elongation from the Sun
24.74° — near the Sun — look low at dusk or dawn

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
2.367 AU
Eccentricity
0.8441
Inclination
1.72°
Orbital period
3.64 years
Perihelion
0.369 AU
Aphelion
4.365 AU
Longitude of ascending node
220.25°
Argument of periapsis
143.35°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 6.0 LD
0.0154 AU
Tisserand (Jupiter)
2.921

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
156
Data arc
11.06 years
First observed
21 January 2015
Last observed
12 February 2026
Residual RMS
0.47 ″
Solution · Otto Matic
8 March 2026

Visual & observation

Absolute magnitude (H)
21.1

Discovery & classification

Apollo Near-Earth Object Potentially Hazardous Asteroid

Close approaches 63 on record

Flyby geometry
Ecliptic flyby of 2015 BL311 at 2029-05-24 12:50 UTC Top-down view of the ecliptic, Earth at the centre, for the 2029-05-24 12:50 UTC close approach of 2015 BL311. Catalogue miss distance 56.8 LD · 2.18 × 10⁷ km. The curve is the geocentric path from 2029-05-21 to 2029-05-27, 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 56.8 LD · 2.18 × 10⁷ km 2029-05-24 12:50 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2029-05-24 12:50 UTC close approach of 2015 BL311. Catalogue miss distance 56.8 LD · 2.18 × 10⁷ km. The curve is the geocentric path from 2029-05-21 to 2029-05-27, 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
2029-05-24 12:50:00 Earth 0.1459 AU 56.8 LD 33.3 km/s
2040-06-13 19:10:00 Venus 0.0868 AU 33.8 LD 27.3 km/s
2052-07-26 13:25:00 Juptr 1.7843 AU 694.4 LD 9.6 km/s
2058-06-01 19:00:00 Earth 0.0187 AU 7.3 LD 28.9 km/s
2064-02-28 01:18:00 Juptr 1.161 AU 451.8 LD 7.2 km/s
2065-10-21 17:40:00 Mercury 0.0726 AU 28.3 LD 22.1 km/s
2065-10-21 17:40:00 Merc 0.0726 AU 28.3 LD 22.1 km/s
2069-06-16 05:41:00 Merc 0.0374 AU 14.6 LD 20.3 km/s
2069-06-16 05:41:00 Mercury 0.0374 AU 14.6 LD 20.3 km/s
2076-10-09 00:15:00 Venus 0.1098 AU 42.7 LD 36.1 km/s

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

Sources