- Earth-watching satellite
- ERS 1
- NORAD 21574
- 1991-050A
- Low Earth orbit
Current orbit
View on live mapOrbit began over the Pacific Ocean
Orbit ends over the Pacific Ocean
In view from you
Nobody watches ERS-1 go over, but a receiver still asks whether it is above the horizon. Say where you are and this card answers.
Your position is rounded to about a kilometre and sent only to the Orbinauts API, to find the pass.
No brightness has been published for ERS-1, so it is not a naked-eye satellite and no city page carries pass times for it. Nothing here estimates one.
Seeing it
There is nothing to go outside for: it is too faint for the naked eye. What it is up there for reaches the ground as pictures and measurements, not as a light in the sky.
Timeline
- Launch
Launched, on the day GCAT records. Source
- Close approach
On Tuesday, Nov 3 at 9:05 AM UTC, Transit 2A (NORAD 45) was to pass within 243 m of ERS 1 (NORAD 21574). The chance was about 1 in 6,000.
Summary
Over the Pacific Ocean LIVE
Where is ERS-1?
At 4:55:18 PM UTC ERS-1 was over the Pacific Ocean (16.3° S, 147.4° W), 744 km up, moving at 7.49 km/s and in sunlight.
What is ERS-1?
A satellite that watches the Earth in low Earth orbit, in space since Jul 17, 1991.
Can I see ERS-1?
No, not with the naked eye: no brightness has been published for ERS-1, and nothing here estimates one; what people use is its pictures and measurements of the Earth.
General
- Operator
- European Space Agency
- State
- European Space Agency
- Built by
- Deutsche Aerospace AG (DASA)-Friedrichsafen (Dornier GmBH)
- What it is
- Earth-watching satellite
- Launched
- Mass
- about 2.4 t
- Operating
- Orbit class
- Low Earth orbit
From GCAT, Jonathan McDowell’s general catalogue, licensed CC BY 4.0: the operator, the state, the manufacturer, what it is for, the launch day, the mass, and whether it is operating. The orbit class is read from its current elements.
Latest orbital data
- Position received
- 4:55 PM UTC
- Station time (UTC)
- 4:55 PM UTC
- Latitude / longitude
- 16.3° S, 147.4° W
- Altitude
- 744 km
- Speed
- 7.49 km/s (26,978 km/h)
- Course
- south
- Light
- In sunlight
- Inclination
- 98.8°
- Orbital period
- 100 minutes
- Orbits per day
- 14.4
- This orbit
- 734 to 780 km
- In shadow
- None of this orbit
- In view from
- Within 2,020 km of the point below it
- Elements epoch
- Nov 8, 2026, 4:20 AM, 12 hours old
- Source
- Position from Space-Track orbital elements of Nov 8, 2026, 4:20 AM, 12 hours old.
No operator publishes an ephemeris for ERS-1, so every position here comes from its orbital elements.
In orbit
- Close approaches
- 1 reported. No close approach to ERS-1 is reported for the next three days.
From Space-Track’s public conjunction messages; the latest report was issued Nov 8, 2026, 1:11 PM, 3 hours old. Only approaches serious enough to be reported publicly are listed: within three days and, for two bodies near the Earth, closer than a kilometre with a chance of a collision above 1 in 10,000, the level at which NASA moves the ISS.
Launched with
ERS-1 shares its launch, 1991-050, with 8 other bodies the catalogue lists in orbit.
| Body | What it is |
|---|---|
| OSCAR 22 (UOSAT 5) | Communications satellite |
| ORBCOMM-X | Communications satellite |
| TUBSAT A | Communications satellite |
| SARA | Space telescope |
| ARIANE 40 R/B | Rocket body |
| ERS 1 DEB | Debris |
| ERS 1 DEB | Debris |
| ERS 1 DEB | Debris |
Read from the international designators of the US catalogue: the year and the launch number every piece of one launch shares. A body that has come down is no longer listed.
Beside the others
| Satellite | Typical altitude | Orbital period | Mass | In space since |
|---|---|---|---|---|
| ERS-1 | 734 to 780 km | 100 minutes | about 2.4 t | 1991 |
| Envisat | 761 to 762 km | 100 minutes | about 8.1 t | 2002 |
| NISAR | 749 to 751 km | 100 minutes | about 2.4 t | 2025 |
| Sentinel-2A | 788 to 790 km | 101 minutes | about 1.1 t | 2015 |
| Sentinel-2B | 788 to 790 km | 101 minutes | about 1.1 t | 2017 |
| Sentinel-2C | 788 to 790 km | 101 minutes | about 1.1 t | 2024 |
Data and API
The current elements from Space-Track as an OMM object, epoch Nov 8, 2026, 4:20 AM, 12 hours old.
{
"OBJECT_NAME": "ERS 1",
"OBJECT_ID": "1991-050A",
"EPOCH": "2026-11-08T04:20:08.440800",
"MEAN_MOTION": 14.39593376,
"ECCENTRICITY": 0.00315798,
"INCLINATION": 98.7713,
"RA_OF_ASC_NODE": 336.35,
"ARG_OF_PERICENTER": 197.7591,
"MEAN_ANOMALY": 162.2494,
"EPHEMERIS_TYPE": 0,
"CLASSIFICATION_TYPE": "U",
"NORAD_CAT_ID": 21574,
"ELEMENT_SET_NO": 999,
"REV_AT_EPOCH": 85076,
"BSTAR": 0.0001323205,
"MEAN_MOTION_DOT": 0.00000369,
"MEAN_MOTION_DDOT": 0
}