Mark Showalter Biography

Showalter leads Hubble observations revealing two previously unknown dusty rings around Uranus and the moons Mab and Cupid.

A Hubble search led by Mark Showalter discovers a fourth moon of Pluto, later named Kerberos.

A follow-up Hubble image confirms the newly detected fourth Pluto moon.

A further Hubble observation again confirms the fourth Pluto moon and strengthens its orbital solution.

A Hubble hazard survey discovers Pluto's fifth and smallest known moon, later named Styx.

Showalter determines a circular orbit for the newly detected moon by tracing it through many archival Hubble images.

Showalter discovers a tiny Neptunian moon in archival Hubble images and initially designates it S/2004 N 1.

The names Kerberos and Styx are adopted for Pluto's fourth and fifth known moons, previously called P4 and P5.

Analysis of the small moons shows rapid, non-synchronous rotation rather than the simple tidal locking seen in Pluto and Charon.

The International Astronomical Union approves the first official names for surface features discovered on Pluto by New Horizons.

Tombaugh Regio and Burney crater become official Pluto feature names honoring Clyde Tombaugh and Venetia Burney.

The tiny moon discovered in Hubble images receives the official name Hippocamp.

Showalter's analysis supports the idea that Hippocamp may be debris broken from the larger moon Proteus by an ancient impact.