NEW YORK, July 16 — Size certainly seems to matter for famed astrophysicist and cosmologist Neil deGrasse Tyson.

The director of the Hayden Planetarium sat down with incoming Late Show host Stephen Colbert to discuss NASA’s New Horizons mission and its recent flyby of Pluto.

In the interview, deGrasse Tyson rained on NASA’s parade by saying he would have been more impressed if the dwarf planet were about 10 per cent bigger.

Colbert took Pluto’s side and rebuffed deGrasse Tyson, saying, “It looks like a planet. It’s got atmosphere; it even has a heart — unlike you, who will give it no love.”

In the video, Colbert describes Pluto as ‘a malted milk ball left in the rain 4.7 billion miles from the sun’ based on photos that the NASA New Horizons spacecraft took during its flyby this week. — Screen grab from YouTube