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Asteroid Near-Earth

2018 BT1

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(2018 BT1)

Where is it now

Distance from Sun
1.125 AU
True anomaly
190.33°
Distance from Earth
1.216 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 2018 BT1 — 1.125 AU from the Sun 2018 BT1
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2018 BT1 is 1.216 AU from Earth today (10.1 light-minutes).

In the sky

Right ascension
09h 42m 21s
Declination
+00° 18′ 13″
Constellation
Sextans
Distance from Earth
1.21 AU
Elongation from the Sun
60.34° — well clear of the Sun

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
0.865 AU
Eccentricity
0.3095
Inclination
29.91°
Orbital period
293.9 days
Perihelion
0.597 AU
Aphelion
1.133 AU
Longitude of ascending node
121°
Argument of periapsis
140.69°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 15.2 LD
0.039 AU
Tisserand (Jupiter)
6.686

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
139
Data arc
7.98 years
First observed
17 January 2018
Last observed
10 January 2026
Residual RMS
0.37 ″
Solution · Otto Matic
10 January 2026

Visual & observation

Absolute magnitude (H)
23.06

Discovery & classification

Aten Near-Earth Object

Close approaches 49 on record

Flyby geometry
Ecliptic flyby of 2018 BT1 at 2047-01-21 08:42 UTC Top-down view of the ecliptic, Earth at the centre, for the 2047-01-21 08:42 UTC close approach of 2018 BT1. Catalogue miss distance 69.6 LD · 2.67 × 10⁷ km. The curve is the geocentric path from 2047-01-18 to 2047-01-24, 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 north of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 69.6 LD · 2.67 × 10⁷ km 2047-01-21 08:42 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2047-01-21 08:42 UTC close approach of 2018 BT1. Catalogue miss distance 69.6 LD · 2.67 × 10⁷ km. The curve is the geocentric path from 2047-01-18 to 2047-01-24, 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 north 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
2045-09-20 05:03:00 Venus 0.1383 AU 53.8 LD 19.2 km/s
2047-01-21 08:42:00 Earth 0.1788 AU 69.6 LD 19.9 km/s
2051-01-23 08:48:00 Earth 0.0597 AU 23.2 LD 17.3 km/s
2055-01-23 08:43:00 Earth 0.0831 AU 32.4 LD 15.8 km/s
2056-03-06 04:22:00 Venus 0.1378 AU 53.6 LD 19.3 km/s
2059-01-20 17:38:00 Earth 0.1947 AU 75.8 LD 15.2 km/s
2066-08-21 10:30:00 Venus 0.1346 AU 52.4 LD 19.3 km/s
2077-02-05 01:57:00 Venus 0.128 AU 49.8 LD 19.3 km/s
2084-01-22 13:21:00 Earth 0.1377 AU 53.6 LD 18.9 km/s
2087-07-22 15:14:00 Venus 0.1311 AU 51.0 LD 19.3 km/s

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

Sources