2014 PN70
A cold classical Kuiper belt object and former New Horizons flyby target.
2014 PN70, referred to as PT3 in New Horizons mission announcements, sits in the cold classical Kuiper belt, a region at the Solar System's outer edge. This object is roughly 40 kilometers (25 miles) across. It was a candidate for a flyby by the New Horizons spacecraft until 2015, when the team chose 486958 Arrokoth instead.
The New Horizons Search Team spotted 2014 PN70 using the Hubble Space Telescope on August 6, 2014. They were hunting for Kuiper belt objects the probe could visit after Pluto. Observations began in June 2014 and intensified through July and August. Because its apparent magnitude is 26.4, ground-based telescopes cannot see it. Initially labeled g12000JZ (nicknamed g1), NASA revealed it as a potential target in October 2014, calling it PT3. The Minor Planet Center didn't assign its official provisional designation, 2014 PN70, until March 2015, once better orbital data was available.
As a trans-Neptunian object, 2014 PN70 is a non-resonant classical Kuiper belt object, or cubewano. It orbits the Sun at distances between 42.1 and 46.6 AU, completing one orbit every 295 years and 4 months (107,886 days), with a semi-major axis of 44.4 AU. Its orbit has an eccentricity of 0.05 and an inclination of 4° relative to the ecliptic, placing it in the "cold population" of cubewanos. The observation arc begins with a precovery image taken by the New Horizons team using the Subaru Telescope at Mauna Kea Observatory six weeks before Hubble's official discovery.
This minor planet has not been numbered by the Minor Planet Center and remains unnamed.
Diameter estimates for 2014 PN70 range from 35 to 55 km (22–34 mi), depending on assumed albedo (0.04 to 0.10). Astronomer Marc Buie gives a similar range of 30–55 km (19–34 mi), while Johnston's archive calculates 39 km. Using a generic magnitude-to-diameter conversion with an absolute magnitude of 10.3 and an albedo of 0.07, the object measures 44 km. Hubble observations show it has a very red color.
After its Pluto flyby, New Horizons needed to visit at least one Kuiper belt object. 2014 PN70 (PT3) was a backup choice to 2014 MU69 (PT1, later named 486958 Arrokoth), since reaching PT3 required more fuel. 2014 OS393 (PT2) was already ruled out. On August 28, 2015, the New Horizons team announced 2014 MU69 as the flyby target.
Quick Facts
- Minorplanet
- yes
- Background
- #C2E0FF
- Discoverer
- New Horizons KBO Search
- Discovery Site
- Hubble Space Telescope
- Discovered
- 6 August 2014 / (first observed only)
- Mpc Name
- 2014 PN · 70
- Mp Category
- TNOcubewano / distant
- Epoch
- 27 April 2019 (JD 2458600.5)
- Uncertainty
- 2
- Observation Arc
- 0.86 yr (313 days)
- Aphelion
- 47.047 AU
- Perihelion
- 42.033 AU
Facts from the source article.
Lore & Background
2014 PN70 was discovered by the New Horizons Search Team during an observation campaign intended to search for KBO flyby targets for the New Horizons probe. Observations began in June 2014, with more intensive ones in July and August, using the Hubble Space Telescope; the object's apparent magnitude of 26.4 is too faint for ground-based telescopes. It was first observed on 6 August 2014, designated g12000JZ (nicknamed g1), and its existence as a potential target was revealed by NASA in October 2014 under the designation PT3. The official provisional designation 2014 PN70 was assigned by the Minor Planet Center in March 2015 after better orbit information became available.
Orbitally, 2014 PN70 is a non-resonant classical Kuiper belt object (cubewano) orbiting the Sun at 42.1–46.6 AU every 295 years and 4 months, with an eccentricity of 0.05 and inclination of 4°, typical of the cold population. Its observation arc begins with a precovery taken by the New Horizons KBO Search team with the Subaru Telescope at Mauna Kea Observatory six weeks before its official discovery. The object has not been numbered or named. Hubble observations show it is very red in color.
Reader's Guide
2014 PN70 is notable primarily as a former candidate for the New Horizons probe's post-Pluto flyby. After completing its Pluto flyby, New Horizons was to perform a flyby of at least one Kuiper belt object. 2014 PN70 (PT3) was considered a second choice after 2014 MU69 (PT1, later named 486958 Arrokoth), because more fuel was required to carry out a flyby. On 28 August 2015, the New Horizons team announced the selection of 2014 MU69 as the next flyby target. Although not selected for a close flyby, 2014 PN70 was observed from greater distances as part of the extended Kuiper belt mission. The spacecraft passed it in March 2019 at a distance of approximately 0.1 AU (15 million km), making it the third closest KBO observed by New Horizons, after Arrokoth and 2014 OS393. New Horizons made its first observations of 2014 PN70 on 5 January 2019 from a distance of 92.7 million km. The spacecraft did not come close enough to resolve the object, but the observations were expected to determine its rotation period and surface properties and to search for possible satellites. These distant observations provide important context for the data collected during the close flyby of Arrokoth.
Did You Know?
- 2014 PN70 was first observed by the New Horizons Search Team using the Hubble Space Telescope on 6 August 2014.
- It was designated PT3 in press releases and was a proposed flyby target for New Horizons until 2015, when 486958 Arrokoth was selected instead.
- The object has an apparent magnitude of 26.4, too faint to be observed by ground-based telescopes.
More in Trans-Neptunian Objects, Part 3 1-24
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