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Trans-Neptunian object

2017 EM4

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(2017 EM4)

Where is it now

Distance from Sun
21.09 AU
True anomaly
145.81°
Distance from Earth
20.864 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 2017 EM4 — 21.09 AU from the Sun 2017 EM4
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2017 EM4 is 20.864 AU from Earth today (2.9 light-hours).

In the sky

Right ascension
02h 00m 24s
Declination
-69° 14′ 35″
Constellation
Hydrus
Distance from Earth
20.87 AU
Elongation from the Sun
101.66° — well clear of the Sun

Favours the southern hemisphere; low or below the horizon from far north.

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
32.848 AU
Eccentricity
0.9201
Inclination
83.52°
Orbital period
188.3 years
Perihelion
2.625 AU
Aphelion
63.071 AU
Longitude of ascending node
346.83°
Argument of periapsis
146.57°
Epoch · J2000
2461200.5
Orbit class · TNO
Trans-Neptunian object
Earth MOID · 681.4 LD
1.7508 AU
Tisserand (Jupiter)
0.381

Orbit quality

Orbit reasonably well determined (uncertainty code 4).

Observations used
47
Data arc
153 days
First observed
23 January 2017
Last observed
25 June 2017
Residual RMS
0.58 ″
Solution · Otto Matic
2 July 2021

Visual & observation

Absolute magnitude (H)
16.03

Discovery & classification

TNO

Sources