Hubble passed its 200,000th orbit and is waiting on a supernova to return

Hubble finished its 200,000th trip around Earth on September 19, 2026, and spent the day pointed at a galaxy cluster where a dead star’s light is expected to turn up again. NASA’s account of the milestone says the observation that day targeted the cluster MACS J0417 and a supernova called Athena.

The orbit count is a round number for a telescope that launched on April 24, 1990 and is still an active NASA mission, so the count itself carries no surprise to astronomers who track it. The supernova is the more open item, because NASA says Athena is expected to reappear between its posting and early March 2027, and the agency has not reported a sighting.

A September 19 milestone with a target attached

According to NASA’s image article, Hubble reached its 200,000th orbit of Earth on September 19, 2026, and the picture released with the milestone shows MACS J0417, the cluster Hubble was observing that day. The agency presents the two facts together: a mission counter rolling over, and the scientific hunt that happened to be underway when it did. Hubble did not pause for the occasion: the observation of MACS J0417 on September 19 is the same one NASA says is monitoring the region for the supernova.

NASA’s Hubble mission page puts the telescope’s scale in numbers: more than 5 billion miles traveled in 36 years of operation and more than 1.7 million observations. It also notes that astronomers request about seven times more observing time each year than Hubble can provide. NASA’s Hubble overview dates the launch to April 24, 1990 and lists the observatory as an active mission, which puts the 200,000 orbits across a little over 36 years in low Earth orbit.

The mission page adds the pace: Hubble circles Earth about 15 times a day, roughly one lap every 95 minutes, at about 300 miles up and 17,000 miles per hour.

Gravitational lensing by MACS J0417

MACS J0417 is a galaxy cluster massive enough to act as a gravitational lens. Its gravity bends and magnifies light from objects far behind it, and because the light can travel several routes of different lengths, NASA says the same supernova can appear multiple times in Hubble’s view, separated by months or even years. In NASA’s telling, the cluster does two jobs at once, brightening the distant explosion enough for Hubble to record it and splitting its light into images that arrive on a staggered schedule.

That is the sense in which Athena is “returning.” The star exploded once; the later image is the same explosion arriving by a longer path. NASA’s mission page says the James Webb Space Telescope discovered Athena in 2025. NASA’s description of that discovery is brief, and the fuller account comes from the VENUS survey, a Webb program imaging 60 galaxy clusters.

Sky & Telescope’s January 2026 report on that survey says Athena sits behind MACS J0417 and was found alongside a second lensed supernova, Ares, behind a different cluster, MACS J0308. For Athena, another image was expected within one to two years of that report. For Ares, two more images are predicted in about 60 years, around 2086. The same report says the survey builds on Hubble’s earlier Frontier Fields program, and that the planned Ares distance measurement would be about 100 times more precise than current lensed-supernova estimates.

The window NASA gave, running to early March 2027

NASA’s own wording for Athena is that it is expected to reappear “between now and early March 2027,” a window written as of the September 19 milestone. That is a range, not a calendar date, and NASA’s pages do not name a day. As of October 4, the agency had published no report that Athena had come back.

Hubble’s job is to be looking when it does. The mission page says tracking the reappearance will help researchers map the mass of MACS J0417 and refine measurements of the expansion rate of the universe, a line of work NASA ties to Hubble’s scientific legacy.

Expansion-rate measurements riding on the delay

Timing the gap between lensed images is a way to measure expansion, and the technique has a precedent in Webb’s earlier find, Supernova Encore. In a December 2023 NASA post, Justin Pierel, then a NASA Einstein Fellow at the Space Telescope Science Institute, and Andrew Newman of the Carnegie Institution for Science described the trains-on-different-routes picture of lensing and said the arrival differences can be used to measure the Hubble constant.

Conor Larison of the Space Telescope Science Institute made a related point about Ares in the Sky & Telescope report, calling the roughly 60-year delay of Ares the most precise time-delay measurement currently known to be possible. Athena’s shorter delay is the one Hubble can actually watch for within a year or two of its discovery, which is why the telescope was aimed at MACS J0417 on its 200,000th orbit.

The one figure still unsettled is the date of the next Athena image, and NASA’s stated bound is early March 2027.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

More from Morning Overview