![298Bap-LB1-mag15](https://upload.wikimedia.org/wikipedia/commons/d/dc/298Bap-LB1-mag15.jpg)
The Baptistina family (
FIN
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...
:
403
Year 403 ( CDIII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Theodosius and Rumoridus (or, less frequently, year 1156 '' Ab ...
) is an
asteroid family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An a ...
of more than 2500 members that was probably produced by the breakup of an
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
across 80 million years ago following an impact with a smaller body. The two largest presumed remnants of the parent asteroid are
main-belt asteroids
298 Baptistina
Baptistina (minor planet designation: 298 Baptistina) is an asteroid orbiting in the asteroid belt. It is the namesake of the Baptistina family. It was discovered on 9 September 1890 by Auguste Charlois of Nice. The source of its name is unkno ...
and
1696 Nurmela. The Baptistina family is part of the larger
Flora clan.
It was briefly speculated that the
Chicxulub impactor was part of the Baptistina family of asteroids, but this was disproven in 2011 using data from the
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...
(WISE).
The Baptistina family consists of darkly colored asteroids and
meteoroids in similar orbits. Many mountain-sized fragments from its initial collision would have leaked into the inner solar system through
orbital resonances with
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
and
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
, causing a prolonged series of asteroid impacts. Previously, this collision was believed to have occurred about 160 million years ago, and many impacts between 100 and 50 million years ago were attributed to it. However, in 2011, data from WISE revised the date of the proposed collision which broke up the parent asteroid to about 80 million years ago.
Composition
It was originally thought that the Baptistina family may consist of uncommon
carbonaceous chondrite
Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 8 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites. The C chondrites represent only a small prop ...
. In 2006, nine asteroids within the Baptistina family were given known classifications: three are
S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second ...
s, two are
X-type asteroids, another two are
A/
R-type asteroid R-type asteroids are moderately bright, relatively uncommon inner-belt asteroids that are spectrally intermediate between the V and A-type asteroids. The spectrum shows distinct olivine and pyroxene features at 1 and 2 micrometres, with a possibil ...
s, 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
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...
of the meteors was known at the time.
Following the impact of the
Chelyabinsk meteor
The Chelyabinsk meteor was a superbolide that entered Earth's atmosphere over the southern Ural (region), Ural region in Russia on 15 February 2013 at about 09:20 Yekaterinburg Time, YEKT (03:20 Coordinated Universal Time, UTC). It was caused ...
in 2013, a paper published in the journal ''
Icarus
In Greek mythology, Icarus (; grc, Ἴκαρος, Íkaros, ) was the son of the master craftsman Daedalus, the architect of the labyrinth of Crete. After Theseus, king of Athens and enemy of Minos, escaped from the labyrinth, King Minos suspe ...
'' showed that shock produced during impact of a large asteroid can darken otherwise bright silicate material. Spectral analysis of the darkly-colored portions of the non-carbonaceous
Chelyabinsk meteorite
The Chelyabinsk meteorite (Russian: Челябинский метеорит, ''Chelyabinskii meteorit'') is the fragmented remains of the large Chelyabinsk meteor of 15 February 2013 which reached the ground after the meteor's passage through t ...
closely matched the color of members of the Baptistina family, showing that a low albedo does not necessarily indicate the composition of the family.
Suspected impacts
In 2007, it was proposed that
chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.
Chromium metal is valued for its high corrosion resistance and hardne ...
concentrations in 66-million-year-old sediment layers at the
Cretaceous–Paleogene boundary
The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K–T) boundary, is a geological signature, usually a thin band of rock containing much more iridium than other bands. The K–Pg boundary marks the end of ...
(K–T boundary) on Earth suggested that the
impactor that gouged out
Chicxulub Crater
The Chicxulub crater () is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is offshore near the community of Chicxulub, after which it is named. It was formed slightly over 66 million years ago when a large ast ...
and caused the
Cretaceous–Paleogene extinction event
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the ...
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.
[Majaess D., Higgins D., Molnar L., Haegert M., Lane D., Turner D., Nielsen I. (2008)]
''New Constraints on the Asteroid 298 Baptistina, the Alleged Family Member of the K/T Impactor''
, accepted for publication in the JRASC One year later, it was discovered that 298 Baptistina does not share the same chemical signature as the source of the
Cretaceous–Paleogene boundary
The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K–T) boundary, is a geological signature, usually a thin band of rock containing much more iridium than other bands. The K–Pg boundary marks the end of ...
.
[Reddy V., et al. (2008)]
''Composition of 298 Baptistina: Implications for K–T Impactor Link''
Asteroids, Comets, Meteors conference. 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 crater
This is a list of craters on Venus, named by the International Astronomical Union's (IAU) Working Group for Planetary System Nomenclature. All craters on Venus are named after famous women or female first names. ''(For features on Venus othe ...
s
Mead
Mead () is an alcoholic beverage made by fermenting honey mixed with water, and sometimes with added ingredients such as fruits, spices, grains, or hops. The alcoholic content ranges from about 3.5% ABV to more than 20%. The defining character ...
,
Isabella
Isabella may refer to:
People and fictional characters
* Isabella (given name), including a list of people and fictional characters
* Isabella (surname), including a list of people
Places
United States
* Isabella, Alabama, an unincorpora ...
,
Meitner, and Klenova.
In 2011, data from the
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...
(WISE) revised the date of the proposed collision which broke up the Baptistina parent asteroid to about 80 million years ago. If correct, this data means it is very unlikely that the
K–T impactor was part of this family of asteroids, as it typically takes many tens of millions of years for an asteroid to reach a resonance with Earth and then collide, much more than the 15 million between this breakup and the collision of the K–T impactor.
"As a result of the WISE science team's investigation, the demise of the dinosaurs remains in the cold case files," said Lindley Johnson, program executive for the
Near Earth Object
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...
Observation Program.
References
External links
* {{cite journal, url=http://astro.mff.cuni.cz/davok/papers/BAF_2007_Supp_Mat.pdf, journal=
Nature
Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...
, title=An Asteroid Breakup 160 My Ago as the Probable Source of the K–T Impactor, last1=Bottke, first1=W. F., last2=Vokrouhlický, first2=D, last3=Nesvorný, first3=D., date=2007-07-06, volume=449, issue=7158, pages=48–53, doi=10.1038/nature06070, pmid=17805288, bibcode=2007Natur.449...48B, s2cid=4322622
Asteroid groups and families
*