background preloader

Dwarf planet

Dwarf planet
Pluto in approximate true colour based on Hubble Space Telescope albedo data A dwarf planet is an object the size of a planet (a planetary-mass object) but that is neither a planet nor a moon or other natural satellite. More explicitly, the International Astronomical Union (IAU) defines a dwarf planet as a celestial body in direct orbit of the Sun[1] that is massive enough for its shape to be controlled by gravity, but that unlike a planet has not cleared its orbit of other objects.[2][3] However, only two of these bodies, Ceres and Pluto, have been observed in enough detail to demonstrate that they actually fit the IAU's definition. The classification of bodies in other planetary systems with the characteristics of dwarf planets has not been addressed.[17] History of the concept[edit] The IAU's final Resolution 5A preserved this three-category system for the celestial bodies orbiting the Sun. Name[edit] Characteristics[edit] *ME in Earth masses. Orbital dominance[edit] Size and mass[edit] Related:  things in space

Eris (dwarf planet) Eris (minor-planet designation 136199 Eris) is the most-massive known dwarf planet in the Solar System and the ninth-most-massive body known to directly orbit the Sun.[d] It is estimated to be 2,326 (±12) km in diameter,[9] and 27% more massive than Pluto, or about 0.27% of the Earth's mass.[10][17] Routine observations were taken by the team on October 21, 2003, using the 1.2 m Samuel Oschin Schmidt telescope at Mount Palomar Observatory, California, but the image of Eris was not discovered at that point due to its very slow motion across the sky: The team's automatic image-searching software excluded all objects moving at less than 1.5 arcseconds per hour to reduce the number of false positives returned. When Sedna was discovered, it was moving at 1.75 arcsec/h, and in light of that the team reanalyzed their old data with a lower limit on the angular motion, sorting through the previously excluded images by eye. Distribution of trans-Neptunian objects

Terrestrial planet Structure[edit] Solar terrestrial planets[edit] Relative masses of the terrestrial planets of the Solar System, including the Moon During the formation of the Solar System, there were probably many more "terrestrial" planetesimals, but most merged with or were ejected by the four terrestrial planets. Density trends[edit] The uncompressed density of a terrestrial planet is the average density its materials would have at zero pressure. The densities of the solar terrestrial planets, the Moon, and the three largest asteroids are shown below. The main exception to this rule is the density of the Moon, which probably owes its lesser density to its unusual origin. It is unknown whether extrasolar terrestrial planets in general will also follow this trend. Extrasolar terrestrial planets[edit] During the early 1990s, the first extrasolar planets were discovered orbiting the pulsar PSR B1257+12, with masses of 0.02, 4.3, and 3.9 times that of Earth's, by pulsar timing. Frequency[edit] Types[edit]

2012 March 12 - The Scale of the Universe Interactive Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2012 March 12 The Scale of the Universe - Interactive Flash Animation Credit & Copyright: Cary & Michael Huang Explanation: What does the universe look like on small scales? On large scales? Tomorrow's picture: dust before galaxies Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)NASA Official: Phillip Newman Specific rights apply.NASA Web Privacy Policy and Important NoticesA service of:ASD at NASA / GSFC& Michigan Tech.

Pluto In 2015, the Pluto system is due to be visited by spacecraft for the first time. The New Horizons probe will perform a flyby during which it will attempt to take detailed measurements and images of the plutoid and its moons. Discovery Discovery photographs of Pluto In the 1840s, using Newtonian mechanics, Urbain Le Verrier predicted the position of the then-undiscovered planet Neptune after analysing perturbations in the orbit of Uranus. In 1906, Percival Lowell, a wealthy Bostonian who had founded the Lowell Observatory in Flagstaff, Arizona in 1894, started an extensive project in search of a possible ninth planet, which he termed "Planet X".[25] By 1909, Lowell and William H. Tombaugh's task was to systematically image the night sky in pairs of photographs taken two weeks apart, then examine each pair and determine whether any objects had shifted position. Name The discovery made headlines across the globe. ), but has a circle in place of the middle prong of the trident ( Other factors

CH star CH stars are particular type of carbon stars which are characterized by the presence of exceedingly strong CH absorption bands in their spectra. They belong to the star population II, meaning they're metal poor and generally pretty middle-aged stars, and are underluminous compared to the classical C–N carbon stars. Many CH stars are known to be binaries, and it's reasonable to believe this is the case for all CH stars. Like Barium stars, they are probably the result of a mass transfer from a former classical carbon star, now a white dwarf, to the current CH-classed star. Sex Chromosome Specialization and Degeneration in Mammals To view the full text, please login as a subscribed user or purchase a subscription. Click here to view the full text on ScienceDirect. Sex chromosomes—particularly the human Y—have been a source of fascination for decades because of their unique transmission patterns and their peculiar cytology. Register an Account If you do not have an account, create one by clicking the button below, and take full advantage of this site's features.

Ceres (dwarf planet) From Earth, the apparent magnitude of Ceres ranges from 6.7 to 9.3, and hence even at its brightest it is too dim to be seen with the naked eye except under extremely dark skies. Piazzi's book "Della scoperta del nuovo pianeta Cerere Ferdinandea" outlining the discovery of Ceres, dedicated the new "planet" to Ferdinand I of the Two Sicilies One of the astronomers selected for the search was Giuseppe Piazzi at the Academy of Palermo, Sicily. By this time, the apparent position of Ceres had changed (mostly due to the Earth's orbital motion), and was too close to the Sun's glare for other astronomers to confirm Piazzi's observations. The early observers were only able to calculate the size of Ceres to within about an order of magnitude. The name Ceres is pronounced /ˈsɪəriːz/ (SEER-eez).[24] The old astronomical symbol of Ceres is a sickle, 〈⚳〉 ( ),[27] similar to Venus's symbol 〈♀〉 but with a break in the circle, with a variant 〈 Ceres (bottom left), the Moon and the Earth, shown to scale

Astrochemistry Astrochemistry is the study of the abundance and reactions of chemical elements and molecules in the universe, and their interaction with radiation.[citation needed] The discipline is an overlap of astronomy and chemistry. The word "astrochemistry" may be applied to both the Solar System and the interstellar medium. The study of the abundance of elements and isotope ratios in Solar System objects, such as meteorites, is also called cosmochemistry, while the study of interstellar atoms and molecules and their interaction with radiation is sometimes called molecular astrophysics. The formation, atomic and chemical composition, evolution and fate of molecular gas clouds is of special interest, because it is from these clouds that solar systems form. Spectroscopy[edit] One particularly important experimental tool in astrochemistry is spectroscopy, the use of telescopes to measure the absorption and emission of light from molecules and atoms in various environments. Research[edit]

Organic farming is rarely enough Organic farming is sometimes touted as a way to feed the world's burgeoning population without destroying the environment. But the evidence for that has been hotly debated. Now, a comprehensive analysis of the existing science, published in Nature1, suggests that farming without the use of chemical fertilizers and pesticides could supply needs in some circumstances. Strawberries are among the few crops that grow almost as well on organic farms as in conventional agriculture. “I think organic farming does have a role to play because under some conditions it does perform pretty well,” says Verena Seufert, an Earth system scientist at McGill University in Montreal, Canada, and the study’s lead author. Area under inspection Seufert's meta-analysis reviewed 66 studies comparing the yields of 34 different crop species in organic and conventional farming systems. Fruitful farming “This is where yield increases are most needed,” says Seufert.

Haumea (dwarf planet) Two teams claim credit for the discovery of Haumea. Mike Brown and his team at Caltech discovered Haumea in December 2004 on images they had taken on May 6, 2004. On July 20, 2005, they published an online abstract of a report intended to announce the discovery at a conference in September 2005.[23] At around this time, José Luis Ortiz Moreno and his team at the Instituto de Astrofísica de Andalucía at Sierra Nevada Observatory in Spain found Haumea on images taken on March 7–10, 2003.[24] Ortiz emailed the Minor Planet Center with their discovery on the night of July 27, 2005.[24] Brown initially conceded discovery credit to Ortiz,[25] but came to suspect the Spanish team of fraud upon learning that his observation logs were accessed from the Spanish observatory the day before the discovery announcement. The proposal by the Ortiz team, Ataecina, did not meet IAU naming requirements, because Ataecina is not a creation deity.

Primary Life Support System A Portable Life Support System from the Apollo A7L suit, with its outer cover removed A Primary (or Portable or Personal) Life Support System (or /Subsystem) (PLSS), is a device connected to an astronaut or cosmonaut's spacesuit, which allows extra-vehicular activity with maximum freedom, independent of a spacecraft's life support system. The PLSS is generally worn like a backpack. The functions performed by the PLSS include: regulating suit pressureproviding breathable oxygenremoving carbon dioxide, humidity, odors, and contaminants from breathing oxygencooling and recirculating oxygen through the pressure garment, and water through a Liquid Cooling and Ventilation Garment or Liquid Cooling Garment.two-way voice communicationdisplay and/or telemetry of suit health parameterstelemetry of an indicator of the wearer's immediate health (e.g. heart rate) Apollo PLSS[edit] The interior of the Apollo PLSS. The PLSS was 26 inches (66 cm) high, 18 inches (46 cm) wide, and 10 inches (25 cm) deep.

10 of the World's Deadliest Plants — And How They Kill You The predator must also, for some reason or another, want to continue to pursue this plant for the toxicity to go so high. Additionally, why this particular poison for that plant? Evolution, fascinating, indeed. I do wonder if any of these are actually the predator. Maybe, the prey provide something that helps promulgates their genes. A lot of plant toxins are geared towards insects. (If you're a plant trying to fend off a moose, poison doesn't do you as much good, because the moose is so big that by the time your poison kills it, the moose has already destroyed you and 15-20 minutes worth of your neighbors. Since insects and mammals share a common (nerve- and muscle-endowed) evolutionary ancestor, there's a fair number of chemicals that can disrupt systems in both groups.

Makemake (dwarf planet) Makemake (minor-planet designation 136,472 Makemake) is a dwarf planet and perhaps the largest Kuiper belt object (KBO) in the classical population,[nb 2] with a diameter that is about 2/3 the size of Pluto.[10][18] Makemake has no known satellites, which makes it unique among the largest KBOs and means that its mass can only be estimated. Its extremely low average temperature, about 30 K (−243.2 °C), means its surface is covered with methane, ethane, and possibly nitrogen ices.[15] Despite its relative brightness (it is about a fifth as bright as Pluto),[nb 3] Makemake was not discovered until well after many much fainter Kuiper belt objects. Most searches for minor planets are conducted relatively close to the ecliptic (the region of the sky that the Sun, Moon and planets appear to lie in, as seen from Earth), due to the greater likelihood of finding objects there. The provisional designation 2005 FY9 was given to Makemake when the discovery was made public.