Related Research Articles
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investigates the deterministic conditions and contingent events with which life arises, distributes, and evolves in the universe.
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth, but is over 95 times more massive.
Titan is the largest moon of Saturn and the second-largest natural satellite in the Solar System. It is the only moon known to have a dense atmosphere, and is the only known object in space other than Earth on which clear evidence of stable bodies of surface liquid has been found.
Cassini–Huygens, commonly called Cassini, was a space-research mission by NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a space probe to study the planet Saturn and its system, including its rings and natural satellites. The Flagship-class robotic spacecraft comprised both NASA's Cassini space probe and ESA's Huygens lander, which landed on Saturn's largest moon, Titan. Cassini was the fourth space probe to visit Saturn and the first to enter its orbit, where it stayed from 2004 to 2017. The two craft took their names from the astronomers Giovanni Cassini and Christiaan Huygens.
Huygens was an atmospheric entry robotic space probe that landed successfully on Saturn's moon Titan in 2005. Built and operated by the European Space Agency (ESA), launched by NASA, it was part of the Cassini–Huygens mission and became the first spacecraft to land on Titan and the farthest landing from Earth a spacecraft has ever made. The probe was named after the 17th-century Dutch astronomer Christiaan Huygens, who discovered Titan in 1655.
Phoebe is an irregular satellite of Saturn with a mean diameter of 213 km (132 mi). It was discovered by William Henry Pickering on March 18, 1899 from photographic plates that had been taken starting on 16 August 1898 at the Boyden Station of the Carmen Alto Observatory near Arequipa, Peru, by DeLisle Stewart. It was the first satellite to be discovered photographically.
The year 2003 was an exciting one for new scientific discoveries and technological breakthroughs progress in many scientific fields. Some of the highlights of 2003, which will be further discussed below, include: the anthropologic discovery of 350,000-year-old footprints attesting to the presence of upright-walking humans; SpaceShipOne flight 11P making its first supersonic flight; the observation of a previously unknown element, moscovium was made; and the world's first digital camera with an organic light-emitting diode (OLED) display is released by Kodak.
The year 1997 in science and technology involved many significant events, listed below.
Methanogenesis or biomethanation is the formation of methane coupled to energy conservation by microbes known as methanogens. Organisms capable of producing methane for energy conservation have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria. Other forms of methane production that are not coupled to ATP synthesis exist within all three domains of life. The production of methane is an important and widespread form of microbial metabolism. In anoxic environments, it is the final step in the decomposition of biomass. Methanogenesis is responsible for significant amounts of natural gas accumulations, the remainder being thermogenic.
The rings of Saturn are the most extensive ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometers to meters, that orbit around Saturn. The ring particles are made almost entirely of water ice, with a trace component of rocky material. There is still no consensus as to their mechanism of formation. Although theoretical models indicated that the rings were likely to have formed early in the Solar System's history, newer data from Cassini suggested they formed relatively late.
A biosignature is any substance – such as an element, isotope, or molecule – or phenomenon that provides scientific evidence of past or present life. Measurable attributes of life include its complex physical or chemical structures and its use of free energy and the production of biomass and wastes. A biosignature can provide evidence for living organisms outside the Earth and can be directly or indirectly detected by searching for their unique byproducts.
The year 2005 in science and technology involved some significant events.
Jonathan I. Lunine is an American planetary scientist and physicist. Lunine teaches at Cornell University, where he is the David C. Duncan Professor in the Physical Sciences and Chair of the Department of Astronomy. Having published more than 380 research papers, Lunine is at the forefront of research into planet formation, evolution, and habitability. His work includes analysis of brown dwarfs, gas giants, and planetary satellites. Within the Solar System, bodies with potential organic chemistry and prebiotic conditions, particularly Saturn's moon Titan, have been the focus of Lunine's research.
The atmosphere of Titan is the dense layer of gases surrounding Titan, the largest moon of Saturn. It is the only thick atmosphere of a natural satellite in the Solar System. Titan's lower atmosphere is primarily composed of nitrogen (94.2%), methane (5.65%), and hydrogen (0.099%). There are trace amounts of other hydrocarbons, such as ethane, diacetylene, methylacetylene, acetylene, propane, PAHs and of other gases, such as cyanoacetylene, hydrogen cyanide, carbon dioxide, carbon monoxide, cyanogen, acetonitrile, argon and helium. The isotopic study of nitrogen isotopes ratio also suggest acetonitrile may be present in quantities exceeding hydrogen cyanide and cyanoacetylene. The surface pressure is about 50% higher than on Earth at 1.5 bars which is near the triple point of methane and allows there to be gaseous methane in the atmosphere and liquid methane on the surface. The orange color as seen from space is produced by other more complex chemicals in small quantities, possibly tholins, tar-like organic precipitates.
Lakes of ethane and methane on Titan, Saturn's largest moon, have been detected by the Cassini–Huygens space probe, and had been suspected long before. The large ones are known as maria (seas) and the small ones as lacūs (lakes).
Michele Karen Dougherty is a Professor of Space Physics at Imperial College London. She is leading unmanned exploratory missions to Saturn and Jupiter and is Principal Investigator for J-MAG – a magnetometer for the European Space Agency's Jupiter Icy Moons Explorer, due for launch in August 2022.
Titan Mare Explorer (TiME) is a proposed design for a lander for Saturn's moon Titan. TiME is a relatively low-cost, outer-planet mission designed to measure the organic constituents on Titan and would have performed the first nautical exploration of an extraterrestrial sea, analyze its nature and, possibly, observe its shoreline. As a Discovery-class mission it was designed to be cost-capped at US$425 million, not counting launch vehicle funding. It was proposed to NASA in 2009 by Proxemy Research as a scout-like pioneering mission, originally as part of NASA's Discovery Program. The TiME mission design reached the finalist stage during that Discovery mission selection, but was not selected, and despite attempts in the U.S. Senate failed to get earmark funding in 2013. A related Titan Submarine has also been proposed.
A planetary surface is where the solid or liquid material of certain types of astronomical objects contacts the atmosphere or outer space. Planetary surfaces are found on solid objects of planetary mass, including terrestrial planets, dwarf planets, natural satellites, planetesimals and many other small Solar System bodies (SSSBs). The study of planetary surfaces is a field of planetary geology known as surface geology, but also a focus of a number of fields including planetary cartography, topography, geomorphology, atmospheric sciences, and astronomy. Land is the term given to non-liquid planetary surfaces. The term landing is used to describe the collision of an object with a planetary surface and is usually at a velocity in which the object can remain intact and remain attached.
David John Southwood is a British space scientist who holds the post of Senior Research Investigator at Imperial College London. He was the President of the Royal Astronomical Society from 2012–2014, and earlier served as the Director of Science and Robotic Exploration at the European Space Agency (2001–2011). Southwood's research interests have been in solar–terrestrial physics and planetary science, particularly magnetospheres. He built the magnetic field instrument for the Cassini Saturn orbiter.
A number of significant scientific events occurred in 2018.
References
- ↑ Brown, P.; Sutikna, T.; Morwood, M. J.; Soejono, R. P.; Jatmiko, Wayhu; Saptomo, E.; Rokus Awe Due (October 27, 2004). "A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia" (PDF). Nature . 431 (7012): 1055–1061. Bibcode:2004Natur.431.1055B. doi:10.1038/nature02999. PMID 15514638. S2CID 26441.
- ↑ Brown, Michael E.; Trujillo, Chadwick; Rabinowitz, David (10 December 2004). "Discovery of a Candidate Inner Oort Cloud Planetoid". The Astrophysical Journal . 617 (1): 645–649. arXiv: astro-ph/0404456 . Bibcode:2004ApJ...617..645B. doi:10.1086/422095. S2CID 7738201.
- ↑ "Chandra :: Photo Album :: Galaxy Clusters and Dark Energy". chandra.harvard.edu. 18 May 2004.
- ↑ Giles, Jim (2005). "Huge explosion traced to exotic star". Nature. doi:10.1038/news050214-18.
- ↑ Koch, George W.; Sillett, Stephen C.; Jennings, Gregory M.; Davis, Stephen D. (2004). "The limits to tree height" (PDF). Nature. 428 (6985): 851–854. Bibcode:2004Natur.428..851K. doi:10.1038/nature02417. PMID 15103376. S2CID 11846291. Archived from the original (PDF) on 2012-10-21. Retrieved 2012-10-08.
- ↑ "Fossil find 'oldest land animal'". BBC News . 2005-01-25. Retrieved 2014-05-25.
- ↑ Daeschler, Edward B.; Shubin, Neil H.; Jenkins, Farish A. Jr (6 April 2006). "A Devonian tetrapod-like fish and the evolution of the tetrapod body plan". Nature . 440 (7085): 757–763. Bibcode:2006Natur.440..757D. doi: 10.1038/nature04639 . PMID 16598249.
- ↑ Kim, E.; Chan, M. H. W. (2004). "Probable observation of a supersolid helium phase". Nature. 427 (6971): 225–227. Bibcode:2004Natur.427..225K. doi:10.1038/nature02220. PMID 14724632. S2CID 3112651.
- ↑ Oganessian, Yu. Ts; Utyonkoy, V. K.; Lobanov, Yu. V.; Abdullin, F. Sh; Polyakov, A. N.; Shirokovsky, I. V.; Tsyganov, Yu. S.; Gulbekian, G. G.; Bogomolov, S. L.; Mezentsev, A. N.; Iliev, S.; Subbotin, V. G.; Sukhov, A. M.; Voinov, A. A.; Buklanov, G. V.; Subotic, K.; Zagrebaev, V. I.; Itkis, M. G.; Patin, J. B.; Moody, K. J.; Wild, J. F.; Stoyer, M. A.; Stoyer, N. J.; Shaughnessy, D. A.; Kenneally, J. M.; Lougheed, R. W. (2004-02-02). "Experiments on the synthesis of element 115 in the reaction 243Am(48Ca,xn)291−x115" (PDF). Physical Review C. 69 (2): 021601. Bibcode:2004PhRvC..69b1601O. doi:10.1103/PhysRevC.69.021601.
- ↑ "Nano-foam makes magnetic debut – physicsworld.com". physicsweb.org.
- ↑ Paredes, Belén; Widera, Artur; Murg, Valentin; Mandel, Olaf; Fölling, Simon; Cirac, Ignacio; Shlyapnikov, Gora V.; Hänsch, Theodor W.; Bloch, Immanuel (2004). "Tonks–Girardeau gas of ultracold atoms in an optical lattice". Nature. 429 (6989): 277–281. Bibcode:2004Natur.429..277P. doi:10.1038/nature02530. PMID 15152247. S2CID 4423003.
- ↑ Plazanet, M.; Floare, C.; Johnson, M. R.; Schweins, R.; Trommsdorff, H. P. (2004). "Freezing on heating of liquid solutions". The Journal of Chemical Physics. 121 (11): 5031–5034. Bibcode:2004JChPh.121.5031P. doi:10.1063/1.1794652. PMID 15352791.
- ↑ Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A. (2004-10-22). "Electric Field Effect in Atomically Thin Carbon Films". Science. 306 (5696): 666–669. arXiv: cond-mat/0410550 . Bibcode:2004Sci...306..666N. doi:10.1126/science.1102896. ISSN 0036-8075. PMID 15499015. S2CID 5729649.
- ↑ "This Month in Physics History: October 22, 2004: Discovery of Graphene". APS News . Series II. 18 (9): 2. October 2009. Retrieved 2016-11-27.