Radar observations of 101 Helena were made from the Arecibo Observatory in what year?
df50243a85d6feb97d5fc1ebf4848dfe
101 Helena 101 Helena is a rocky main-belt asteroid. It was discovered by Canadian-American astronomer J. C. Watson on August 15, 1868, and was named after Helen of Troy in Greek mythology. Radar observations were made of this object on Oct 7 and 19, 2001 from the Arecibo Observatory. Analysis of the data gave an estimated ellipsoidal diameter of 71×63×63 ± 16% km. The diameter estimated from IRAS infrared measurements is 66 km. It is classified as an S-type asteroid in the Tholen system.
b6b147fa6c7ec4e6cf48307b5c1efd3e
Arecibo Observatory The Arecibo Observatory is a radio telescope in the municipality of Arecibo, Puerto Rico. This observatory is operated by SRI International, USRA and UMET, under cooperative agreement with the National Science Foundation (NSF). The observatory is the sole facility of the National Astronomy and Ionosphere Center (NAIC), which refers to the observatory, and the staff that operates it. From its construction in the 1960s until 2011, the observatory was managed by Cornell University.
07adc8acf6a30bd95a2b0728abbb18c0
Guido d'Arezzo (crater) Guido d'Arezzo is a crater on Mercury. It has a diameter of 66 kilometers. Its name was adopted by the International Astronomical Union in 1976. Guido d'Arezzo is named for the Italian music theorist Guido of Arezzo, who lived from 990 to 1050.
000f5e647abee720db44d50eba31753f
Rozhen Observatory Rozhen Observatory (Bulgarian: Национална астрономическа обсерватория - Рожен , "НАО-Рожен"; English: National Astronomical Observatory - Rozhen , "NAO-Rozhen"), also known as the Bulgarian National Astronomical Observatory, is an astronomical observatory, located in the Smolyan Province, 90 kilometers south of the city of Plovdiv, Bulgaria. The nearest town, Chepelare, is 15 kilometers away. The observatory is owned and operated by the Institute of Astronomy of the Bulgarian Academy of Sciences (BAS). It was officially opened on 13 March 1981, almost 20 years after Bogomil Kovachev – a professor of astronomy at BAS, known as its founder – had started working towards that goal. The Observatory is the largest in Southeastern Europe and has an active team of about 50 astronomers. It is the principal center for astronomical research in Bulgaria. The minor planet 6267 Rozhen, was discovered at, and named after the observatory.
3477971cf308c25e7aad56262e254d7d
4769 Castalia The asteroid 4769 Castalia ( ; previously known by the provisional designation 1989 PB) was the first asteroid to be modeled by radar imaging. It is an Apollo, Mars- and Venus-crosser asteroid. It was discovered on August 9, 1989, by Eleanor F. Helin (Caltech) on photographic plates taken at Palomar Observatory. It is named after Castalia, a nymph in Greek mythology.
4e5b330dd23201a85c73f98e17202eee
The Castle (Saint Helena) The Castle is the main government building of the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha, located in Jamestown on the island of Saint Helena. A Grade I-listed building, the oldest parts of the complex date to 1708, but it was largely reconstructed in the 1860s because of termite damage. It does not have the appearance of a typical castle, though historically the site was part of the East India Company fortifications of Jamestown.
928117bfd58a86cefbc9163d4a390032
1924 Cuba hurricane The 1924 Cuba hurricane is the earliest officially classified Category 5 Atlantic hurricane on the Saffir–Simpson scale, and one of two hurricanes to make landfall on Cuba at Category 5 intensity, the other being Hurricane Irma in 2017. It formed on October 14 in the western Caribbean, slowly organizing as it tracked northwestward. By October 16, it attained hurricane status to the east of the Yucatán Peninsula, and subsequently executed a small counterclockwise loop. On October 18, the hurricane began undergoing rapid deepening, and the next day it reached an estimated peak intensity of 165 mph (270 km/h). Shortly thereafter, it struck extreme western Cuba at peak intensity, becoming the strongest hurricane on record to hit the country. Later the hurricane weakened greatly, striking southwestern Florida with winds of 90 mph (150 km/h) in a sparsely populated region. While crossing the state it weakened to tropical storm status, and after accelerating east-northeastward, it was absorbed by a cold front on October 23 south of Bermuda.
6709e7bf9cb1d4a0e62d0f9d7fa49786
1939 Atlantic hurricane season The 1939 Atlantic hurricane season officially began on June 12, 1939, and lasted until November 7, 1939. These dates mark the period of each year when most tropical cyclones form in the Atlantic basin. The 1939 season had below normal activity, with only six tropical storms, of which two became hurricanes and one became a major hurricane, equivalent to Category 3 status or higher on the modern-day Saffir-Simpson Hurricane Scale. The first tropical cyclone formed on June 12, and the last dissipated on November 6.
859a31a0077e55d22089613d42c5d904
(277475) 2005 WK4 (277475) 2005 WK is a near-Earth asteroid that passed within 8.2 Lunar distances on August 8, 2013. It was radar-imaged by the Deep Space Network dish at Goldstone, USA. The asteroid is between 660 and 980 feet (200 and 300 meters) in diameter, and rotated 2.5 times in 6.5 hours. It had been observed by the Arecibo radar in July 2012 (this was not a close approach though), and is also classified as a Potentially Hazardous Object (PHA). The asteroid was discovered November 27, 2005 by the Siding Spring Survey.
181c4a2d2843bc201920427d426cfc8c
Global Drifter Program The Global Drifter Program (GDP) (formerly known as the Surface Velocity Program (SVP)), was conceived by Prof. Peter Niiler, with the objective of collecting measurements of surface ocean currents, sea surface temperature and sea-level atmospheric pressure using drifters. It is the principal component of the Global Surface Drifting Buoy Array, a branch of NOAA's Global Ocean Observing System (GOOS) and a scientific project of the Data Buoy Cooperation Panel (DBCP). The project originated in February 1979 as part of the TOGA/Equatorial Paciﬁc Ocean Circulation Experiment (EPOCS) and the first large-scale deployment of drifters was in 1988 with the goal of mapping the tropical Pacific Ocean's surface circulation. The current goal of the project is to use 1250 satellite-tracked surface drifting buoys to make accurate and globally dense in-situ observations of mixed layer currents, sea surface temperature, atmospheric pressure, winds and salinity, and to create a system to process the data. Horizontal transports in the oceanic mixed layer measured by the GDP are relevant to biological and chemical processes as well as physical ones.
47b1c1451392916119a9076234439d0f
Goldstone Solar System Radar The Goldstone Solar System Radar, or GSSR, is a large radar system used for investigating objects in the Solar system. Located in the desert near Barstow, California, it comprises a 500-kW X-band (8500 MHz) transmitter and a low-noise receiver on the 70-m DSS 14 antenna at the Goldstone Deep Space Communications Complex. It has been used to investigate Mercury, Venus, Mars, the asteroids, and moons of Jupiter and Saturn. The most comparable facility is the radar at Arecibo Observatory.
cc2e23030285493e67f1a2700eeefb47
Nightingale Island Nightingale Island is an active volcanic island in the South Atlantic Ocean, 3 km2 in area, part of the Tristan da Cunha group of islands. They are administered by the United Kingdom as part of the overseas territory of Saint Helena, Ascension and Tristan da Cunha.
499b1b2c5f9ada8cd63d54005dcc6e42
John Carroll (astronomer) Sir John Anthony Carroll {'1': ", '2': ", '3': ", '4': "} (8 January 1899 – 2 May 1974) was a British astronomer and physicist. In the 1920s he worked at the Solar Physics Observatory, Cambridge, UK with F.J.M. Stratton and Richard van der Riet Woolley. He made major technological advances, inventing a high resolution spectrometer, and (with C G Fraser) a "coronal camera".
e2fc20626301050f710629cb0141fc6b
Per-Simon Kildal Per-Simon Kildal (4 July 1951 – 21 April 2016) was professor of antenna systems at Chalmers University of Technology in Sweden, IEEE fellow and the winner of "Distinguished Achievement Award" of the IEEE Antennas and Propagation Society in 2011. Kildal had contributed to design of reflector antennas for radio astronomy worldwide, most notably the Gregorian reflector of Arecibo Observatory which was installed in 1997. Apart from reflector antennas, he had made contributions to wideband radiotelescope feeds, Over-The-Air (OTA) measurements of the antennas and metamaterial applications.
9226912a2f59103ca5afcd784c74d2f7
John Paul Wild Dr John Paul (Paul) Wild AC CBE MA ScD (Cantab.) FRS FTSE FAA (17 May 192310 May 2008) was a British-born Australian scientist. Following service in World War II as a radar officer in the Royal Navy, he became a radio astronomer in Australia for the Council for Scientific and Industrial Research, the fore-runner of the Commonwealth Scientific and Industrial Research Organisation (CSIRO). In the 1950s and 1960s he made discoveries based on radio observations of the Sun. In the late 1960s and early 1970s his team built and operated the world's first solar radio-spectrographs and subsequently the Culgoora radio-heliograph, near Narrabri, New South Wales. The Paul Wild Observatory at Culgoora is named after him.
e4d46c793b73954dcd68a99a94e34ee4
ANTARES (telescope) ANTARES is the name of a neutrino detector residing 2.5 km under the Mediterranean Sea off the coast of Toulon, France. It is designed to be used as a directional neutrino telescope to locate and observe neutrino flux from cosmic origins in the direction of the Southern Hemisphere of the Earth, a complement to the South Pole neutrino detector IceCube that detects neutrinos from both hemispheres. The name comes from Astronomy with a Neutrino Telescope and Abyss environmental RESearch project; the acronym is also the name of the prominent star Antares. Other neutrino telescopes designed for use in the nearby area include the Greek NESTOR telescope and the Italian NEMO telescope, which are both in early design stages.
5bb8c3da244048fe4a5286d1f5e06ecf
Hurricane Irene–Olivia Hurricane Irene–Olivia was the first actively tracked tropical cyclone to move into the eastern Pacific Ocean from the Atlantic basin. It originated as a tropical depression on September 11, 1971, in the tropical Atlantic. The cyclone tracked nearly due westward at a low latitude, passing through the southern Windward Islands and later over northern South America. In the southwest Caribbean Sea, it intensified to a tropical storm and later a hurricane. Irene made landfall on southeastern Nicaragua on September 19, and maintained its circulation as it crossed the low-lying terrain of the country. Restrengthening after reaching the Pacific, Irene was renamed Hurricane Olivia, which ultimately attained peak winds of 115 mph (185 km/h). Olivia weakened significantly before moving ashore on the Baja California Peninsula on September 30; the next day it dissipated.
afbcc46551df77af981ddb4252571659
Saint Helena referendum, 2002 A referendum on building a new airfield or replacing RMS St Helena was held in Saint Helena between 21 January and 1 February 2002. Around 72% voted in favour of the airport, although critics claimed that the referendum was slanted in favour of this option.
dc7ee6b8738aaeec70bad1ca11ff4e92
Rossby whistle The Rossby whistle is the oscillation of sea-level and bottom pressure in the Caribbean Sea with the period of 120 days and influenced by propagating westward oceanic Rossby wave.
26bab2b9439badf04b8f9ae444b041c3
Observatory Naef Épendes Observatory Robert A. Naef (French: Observatoire Robert-A. Naef ) is an astronomical observatory located at Épendes, Canton of Fribourg, Switzerland at 7.13938 degrees east of Greenwich and 46.7326 degrees north latitude. Its parallax constants are : ρ sin φ' = 0.68632 (Earth radii from the rotation axis) and ρ cos φ' = +0.72501 (Earth radii from the equatorial plane).
99c5c58f57c6558fe7f80efd6ddb3fa7
Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space observatory launched on STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope, enabled by the high angular resolution of its mirrors. Since the Earth's atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes; therefore space-based telescopes are required to make these observations. Chandra is an Earth satellite in a 64-hour orbit, and its mission is ongoing as of 2017 .
500306e36fbf093513bdcf2c3010deb4
Long Michelson Interferometer The Long Michelson Interferometer was a radio telescope interferometer built by Martin Ryle and co-workers in the late 1940s beside the rifle range to the west of Cambridge, England. The interferometer consisted of 2 fixed elements 440m apart to survey the sky using Earth rotation. It produced the Preliminary survey of the radio stars in the Northern Hemisphere at 45 MHz - 214 MHz. The telescope was operated by the Radio Astronomy Group of Cambridge University.