1
|
Meech KJ, Yang B, Kleyna J, Hainaut OR, Berdyugina S, Keane JV, Micheli M, Morbidelli A, Wainscoat RJ. Inner solar system material discovered in the Oort cloud. SCIENCE ADVANCES 2016; 2:e1600038. [PMID: 27386512 PMCID: PMC4928888 DOI: 10.1126/sciadv.1600038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/30/2016] [Indexed: 05/31/2023]
Abstract
We have observed C/2014 S3 (PANSTARRS), a recently discovered object on a cometary orbit coming from the Oort cloud that is physically similar to an inner main belt rocky S-type asteroid. Recent dynamical models successfully reproduce the key characteristics of our current solar system; some of these models require significant migration of the giant planets, whereas others do not. These models provide different predictions on the presence of rocky material expelled from the inner solar system in the Oort cloud. C/2014 S3 could be the key to verifying these predictions of the migration-based dynamical models. Furthermore, this object displays a very faint, weak level of comet-like activity, five to six orders of magnitude less than that of typical ice-rich comets on similar Orbits coming from the Oort cloud. For the nearly tailless appearance, we are calling C/2014 S3 a Manx object. Various arguments convince us that this activity is produced by sublimation of volatile ice, that is, normal cometary activity. The activity implies that C/2014 S3 has retained a tiny fraction of the water that is expected to be present at its formation distance in the inner solar system. We may be looking at fresh inner solar system Earth-forming material that was ejected from the inner solar system and preserved for billions of years in the Oort cloud.
Collapse
Affiliation(s)
- Karen J. Meech
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
| | - Bin Yang
- European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago, Chile
| | - Jan Kleyna
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
| | - Olivier R. Hainaut
- European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
| | - Svetlana Berdyugina
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
- Kiepenheuer Institut fuer Sonnenphysik, Schoeneckstrasse 6, 79104 Freiburg, Germany
| | - Jacqueline V. Keane
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
| | - Marco Micheli
- Space Situational Awareness (SSA)–Near Earth Objects (NEO) Coordination Centre, European Space Agency, 00044 Frascati (RM), Italy
- SpaceDyS s.r.l., 56023 Cascina (Pl), Italy
- Istituto Nazionale di Astrofisica (INAF)–Istituto di Astrofisica e Planetologia Spaziali (IAPS), 00133 Roma (RM), Italy
| | - Alessandro Morbidelli
- Laboratoire Lagrange, UMR 7293, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Cöte d’Azur, Boulevard de l’Observatoire, 06304 Nice Cedex 4, France
| | - Richard J. Wainscoat
- Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822–1839, USA
| |
Collapse
|
3
|
Bottke WF, Vokrouhlický D, Nesvorný D. An asteroid breakup 160 Myr ago as the probable source of the K/T impactor. Nature 2007; 449:48-53. [PMID: 17805288 DOI: 10.1038/nature06070] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 06/22/2007] [Indexed: 11/08/2022]
Abstract
The terrestrial and lunar cratering rate is often assumed to have been nearly constant over the past 3 Gyr. Different lines of evidence, however, suggest that the impact flux from kilometre-sized bodies increased by at least a factor of two over the long-term average during the past approximately 100 Myr. Here we argue that this apparent surge was triggered by the catastrophic disruption of the parent body of the asteroid Baptistina, which we infer was a approximately 170-km-diameter body (carbonaceous-chondrite-like) that broke up 160(-20)+30Myr ago in the inner main asteroid belt. Fragments produced by the collision were slowly delivered by dynamical processes to orbits where they could strike the terrestrial planets. We find that this asteroid shower is the most likely source (>90 per cent probability) of the Chicxulub impactor that produced the Cretaceous/Tertiary (K/T) mass extinction event 65 Myr ago.
Collapse
Affiliation(s)
- William F Bottke
- Southwest Research Institute, 1050 Walnut St, Suite 300, Boulder, Colorado 80302, USA.
| | | | | |
Collapse
|
4
|
Wasson JT. Large aerial bursts: an important class of terrestrial accretionary events. ASTROBIOLOGY 2003; 3:163-179. [PMID: 12809134 DOI: 10.1089/153110703321632499] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Large aerial bursts similar to the 1908 Tunguska bolide but much larger in magnitude have surely been responsible for many catastrophic events in the history of the Earth. Because aerial bursts produce shallow (or even negligible) craters, their existence is difficult to document in the geological record. Even aerial bursts as small as Tunguska deposit enough energy to melt approximately 1mm of dry soil. Silica-rich glass formed in such melts has the potential to survive in the soil for many Ma, thus a potential indicator of large aerial bursts is glass that was formed as thick regions within silicate melt sheets. The layered tektites from Southeast Asia and the Libyan desert glass may have formed by a combination of sedimentation and downslope flow of silicate melt heated by radiation from large aerial bursts. The alternative, formation of layered tektites as crater ejecta, cannot account for observations such as uniformly high 10Be contents, the orientation of the magnetic remanence field, and the absence of splash-form (e.g., teardrop or dumbbell) tektites in regions where layered tektites are common. The largest asteroids or comets make craters no matter what their strength. Recent reviews suggest that, for events in the energy range up to 10(19)-10(20) J (about two orders of magnitude larger than the Meteor Crater impact), aerial bursts are more likely than cratering events, and the layered tektites of Southeast Asia imply the existence of aerial bursts one to two orders of magnitude larger still.
Collapse
Affiliation(s)
- John T Wasson
- Institute of Geophysics and Planetary Physics and Department of Earth and Space Sciences, University of California, Los Angeles 90095-1567, USA.
| |
Collapse
|
5
|
Brown P, Spalding RE, ReVelle DO, Tagliaferri E, Worden SP. The flux of small near-Earth objects colliding with the Earth. Nature 2002; 420:294-6. [PMID: 12447433 DOI: 10.1038/nature01238] [Citation(s) in RCA: 340] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2002] [Accepted: 10/21/2002] [Indexed: 11/09/2022]
Abstract
Asteroids with diameters smaller than approximately 50-100 m that collide with the Earth usually do not hit the ground as a single body; rather, they detonate in the atmosphere. These small objects can still cause considerable damage, such as occurred near Tunguska, Siberia, in 1908. The flux of small bodies is poorly constrained, however, in part because ground-based observational searches pursue strategies that lead them preferentially to find larger objects. A Tunguska-class event-the energy of which we take to be equivalent to 10 megatons of TNT-was previously estimated to occur every 200-300 years, with the largest annual airburst calculated to be approximately 20 kilotons (kton) TNT equivalent (ref. 4). Here we report satellite records of bolide detonations in the atmosphere over the past 8.5 years. We find that the flux of objects in the 1-10-m size range has the same power-law distribution as bodies with diameters >50 m. From this we estimate that the Earth is hit on average annually by an object with approximately 5 kton equivalent energy, and that Tunguska-like events occur about once every 1,000 years.
Collapse
Affiliation(s)
- P Brown
- Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7, Canada.
| | | | | | | | | |
Collapse
|
6
|
Affiliation(s)
- Mark E Bailey
- Armagh Observatory, College Hill, Armagh BT61 9DG, Northern Ireland, UK.
| |
Collapse
|