Baptistina family

298 Baptistina is the namesake asteroid and largest presumed remnant of the Baptistina family. It was discovered on 9 September 1890 by Auguste Charlois at the Nice Observatory. The source of its name is unknown. It measures about in diameter. Although it has an orbit similar to the Flora family asteroids, Baptistina is an unrelated interloper. Other members of the Baptistina family include 1696 Nurmela, 2858 Carlosporter, and (7255) 1993 VY1. ==Composition==

It was originally thought that the Baptistina family may consist of uncommon carbonaceous chondrite. In 2006, nine asteroids within the Baptistina family were given known classifications: three are S-type asteroids, two are X-type asteroids, another two are A/R-type asteroids, one is C-type and one is V-type. However, any conclusions taken from this were highly speculative, as very few members in the family were classified, and not even the albedo of the meteors was known at the time. == Formerly proposed impacts ==

In 2007, it was proposed that chromium concentrations in 66-million-year-old sediment layers at the Cretaceous–Paleogene boundary (K–T boundary) on Earth suggested that the impactor that gouged out Chicxulub Crater and caused the Cretaceous–Paleogene extinction event belonged to the Baptistina family. Concerns were raised regarding the reputed link, in part because very few solid observational constraints existed of the asteroid or family. One year later, it was discovered that 298 Baptistina does not share the same chemical signature as the source of the Cretaceous–Paleogene boundary. Because of the timeframe, it had also been suggested that the impactor that produced the lunar crater Tycho 108 million years ago was also a member of the group, as well as the Venusian craters Mead, Isabella, Meitner, and Klenova. == References ==