Where could New Horizons visit after it flies by Pluto next year? NASA’s Hubble Space Telescope is on the case. In a program that pushed the limits of the 24-year-old observatory, Hubble found three potential Kuiper Belt Objects for the spacecraft to visit.

The wrinkle is there is no money approved yet for New Horizons to do an extended mission yet, but team members (including Alex Parker from the Southwest Research Institute, who is quoted from Twitter below) are celebrating the milestone. To them, the most promising target (PT1) is the one on the left of the images you see above. Read more about it below the jump.

The Kuiper Belt is a zone of icy objects about four billion miles (6.4 billion kilometers) from the Sun, considered to be leftovers of the building blocks that put together the Solar System billions of years ago. It’s an area that Pluto itself drifts through from time to time on its elliptical orbit around the Sun. Roughly 1,000 objects there have been cataloged, although many more are believed to exist.

The team used Hubble from June 16 to 26 in a test program to look at 20 sky zones for evidence of KBOs, finding two that had never been spotted before by ground-based telescopes. More searching between July and September revealed one object that is “definitely reachable”, NASA stated, and two others that require more scrutiny.

We estimate that PT1 is several 10s of kilometers across. Here’s what that looks like next to Cape Cod and #Comet67P: pic.twitter.com/IHUx6uymO7 — Alex Parker (@Alex_Parker) October 15, 2014

Here is where PT1 lies in relation to the rest of the solar system. The yellow path is New Horizons’ trajectory. pic.twitter.com/4aQDEj8oPZ — Alex Parker (@Alex_Parker) October 15, 2014

Here is a gif of the Hubble Space Telescope discovery images of our New Horizons-targetable Kuiper Belt Object PT1. http://t.co/ifw8I4a8Wz — Alex Parker (@Alex_Parker) October 15, 2014

An important and sobering note: even though New Horizons can reach this Kuiper Belt Object, there is no guarantee of an extended mission. — Alex Parker (@Alex_Parker) October 15, 2014

Each of the three candidates would take a while to reach, as they are all about one billion miles (1.6 billion km) beyond Pluto. They’re also tiny, with two estimated at 34 miles (55 kilometers) across and the third at 15 miles (25 kilometers). This makes them 10 times bigger than the average comet, but only 1-2% the size of small Pluto.

“This was a needle-in-haystack search for the New Horizons team because the elusive KBOs are extremely small, faint, and difficult to pick out against a myriad background of stars in the constellation Sagittarius, which is in the present direction of Pluto,” NASA wrote in a press release.

New Horizons’ team plans to ask for the extended mission in late 2016. Meanwhile, the spacecraft (which has been flying ever outwards since 2006) will finally zoom past its main target of Pluto in July 2015.