02 - Full Moon
at 19:14 UT
05 - Taurid
(south) meteor shower peaks. Active
between 25 Sept and 25 Nov.
Associated with Comet 2P/Encke.
09 - Moon near
Mars (morning sky) at 14h UT. Mag. +0.3.
12 -Taurid (north) meteor
shower peaks. May produce the occasional
17 -Leonid meteor shower
peaks at 9h UT. Arises from debris ejected
Comet Tempel-Tuttle in 1533. Expect about 25
to 30 meteors per hour under
dark skies. Predictions of enhanced activity
between 21-22h UT on 17 Nov
(favours sky watchers in Asia).
21 -Alpha Monocerotid meteor
shower peaks at 15:25 UT. A usually minor
shower active 15-25 Nov. Radiant is near Procyon.
Predictions of enhanced
activity this year. Timing favours Far East
Asia, Australia and across the
Pacific to Alaska.
00 0 0
0 0 0//
Get the complete calendar version
Friday, July 31, 2009
Bright Spot on Venus Stumps Scientists
A montage of ultraviolet images taken during several Venus Express orbit with the Venus Monitoring Camera (VMC) (each orbit is 24 hours long).
A sudden bright spot that appeared in the clouds of Venus just days after a comet left a bruise on Jupiter has scientists stumped as to its cause.
Venus' bright spot, first noticed by amateur astronomer Frank Melillo of Holtsville, NY on July 19, is not the first such brightening noticed on our cloudy neighbor, said planetary scientist Sanjay Limaye of the University of Wisconsin-Madison. This time is a little different though because the brightening is confined to a smaller region, Limaye said. It also came in the wake of Jupiter's own new (dark) spot, believed to be the result of a comet impact — Limaye attributes the fortunate confluence of the two events for the attention Venus is now getting in the astronomical community.After Melillo reported the spot, other amateur astronomers and the European Space Agency's (ESA) Venus Express spacecraft confirmed the presence of the blemish.The new Venus Express images show that the bright spot actually appeared in the planet's southern hemisphere four days before Melillo saw it and that it has since begun to spread out, becoming stretched by the wind's in Venus' thick atmosphere. But just what caused the brightening is still a mystery. Theories have abounded, from a volcanic eruption to solar particles interacting with the planet's atmosphere.
Armchair astronomers have helped discover a batch of tiny galaxies that may help professional astronomers understand how galaxies formed stars in the early universe.
Dubbed the "Green Peas," the galaxies are forming stars 10 times faster then the Milky Way despite being 10 times smaller and 100 times less massive. They are between 1.5 billion and 5 billion light years away. The discoveries were made as part of a project called Galaxy Zoo, where Internet users volunteer their spare time to help classify galaxies for an online image database.
Murmurs of a potential discovery began when a group of volunteers who called themselves the "Peas Corps" and the "Peas Brigade" started a discussion in an online forum about a group of strange bright green objects. The original forum thread was called "Give peas a chance."
The volunteers – many of whom had no previous astronomy background or experience – were asked to refine their image samples and submit them to a lab for color analysis. Once the findings were verified, researchers analyzed the light emanating from the galaxies to determine the degree of star formation taking place within them.
Nasa finds monster black hole sucking up gas, dust and stars at centre of galaxy
The galaxy NGC-1097 with a monstrous black hole surrounded by a ring of stars at its centre Photo: REUTERS / NASA
Nasa has found a monster black hole 100 million times the mass of the Sun feeding off gas, dust and stars at the centre of a galaxy 50 million light-years away. The star-ringed black hole forms the eye of a galaxy called NGC-1097 which was photographed by the US space agency's Spitzer Space Telescope in California.
A black hole is a region of space in which the gravitational pull is so powerful that nothing, including whole planets, can escape being sucked in if they come within its reach. The galaxy in the photograph is spiral-shaped, like our Milky Way, and extends long arms of red stars into space. But Nasa said the black hole at the centre of the galaxy in which Earth is situated is tame by comparison to NGC-1097, with the mass of just a few million suns. The picture shows a fiery ring around the black hole which is packed with brightly-burning newborn stars. The galaxy's red spiral arms and swirling spokes between them show dust heated by newborn stars, while older populations of stars scattered through the galaxy are blue. A fuzzy blue dot to the left of the image shows a companion galaxy, while other dots are either stars in the Milky Way, or other more distant galaxies.
IT LOOKS like a soap bubble or perhaps even a camera fault, but the image at right is a newly discovered planetary nebula.
Dave Jurasevich of the Mount Wilson Observatory in California spotted the "Cygnus Bubble" while recording images of the region on 6 July 2008. A few days later, amateur astronomers Mel Helm and Keith Quattrocchi also found it.
The bubble, which was officially named PN G75.5+1.7 last week, has been there a while. A closer look at images from the second Palomar Sky Survey revealed it had the same size and brightness 16 years ago. Jurasevich thinks it was overlooked because it is very faint.
Planetary nebulae, which got their name after being misidentified by early astronomers, are formed when an ageing star weighing up to eight times the mass of the sun ejects its outer layers as clouds of luminous gas. Most are elliptical, double-lobed or cigar-shaped, evolving after stars eject gas from each pole.
Source: Newscientist.com Image credit: Travis A. Rector/U of Alaska Anchorage/Heidi Schweiker/NOAO
Hawaii was chosen Tuesday as the site for the world's biggest telescope, a device so powerful that it will allow scientists to see some 13 billion light years away and get a glimpse into the early years of the universe.
The telescope's mirror — stretching almost 100 feet in diameter, or nearly the length of a Boeing 737's wingspan — will be so large that it should be able to gather light that will have spent 13 billion years traveling to earth. This means astronomers looking into the telescope will be able to see images of the first stars and galaxies forming — some 400 million years after the Big Bang.
The telescope, expected to be completed by 2018, will be located atop a dormant volcano that is popular with astronomers because its summit sits well above the clouds at 13,796 feet, offering a clear view of the sky above for 300 days a year.
This image shows a large impact on Jupiter's south polar region captured on July 20, 2009, by NASA's Infrared Telescope Facility in Mauna Kea, Hawaii. Image credit: NASA/JPL/Infrared Telescope Facility
Scientists have found evidence that another object has bombarded Jupiter, exactly 15 years after the first impacts by the comet Shoemaker-Levy 9.
Following up on a tip by an amateur astronomer, Anthony Wesley of Australia, that a new dark "scar" had suddenly appeared on Jupiter, this morning between 3 and 9 a.m. PDT (6 a.m. and noon EDT) scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., using NASA's Infrared Telescope Facility at the summit of Mauna Kea, Hawaii, gathered evidence indicating an impact.
New infrared images show the likely impact point was near the south polar region, with a visibly dark "scar" and bright upwelling particles in the upper atmosphere detected in near-infrared wavelengths, and a warming of the upper troposphere with possible extra emission from ammonia gas detected at mid-infrared wavelengths.
Apollo 14: Science instruments (circled left) and the lunar module descent stage (circled right) are connected by a footprint trail
A US spacecraft has captured images of Apollo landing sites on the Moon, revealing hardware and a trail of footprints left on the lunar surface. The release of the images coincides with the 40th anniversary of the first manned mission to land on the Moon. The descent stages from the lunar modules which carried astronauts to and from the Moon can clearly be seen. The image of the Apollo 14 landing site shows scientific instruments and an astronaut footpath in the lunar dust. It is the first time hardware left on the Moon by the Apollo missions has been seen from lunar orbit. The pictures were taken by Nasa's Lunar Reconnaissance Orbiter (LRO) spacecraft, which launched on 18 June.
Mars Dust Devil Has Colorful Effect in Image Series
Scientists have combined a trio of shots taken seconds apart through different colored filters to create a special-effects portrait of a moving dust devil on Mars.
The panoramic camera on NASA's Mars Exploration Rover Spirit was taking exposures through different filters during the 1,919th Martian day of Spirit's mission (May 27, 2009) as part of constructing a large color panorama. Three westward shots, with several seconds intervening between them, caught a whirlwind in motion. A composite image combining the three exposures to make a color image of the Martian ground shows the dust devil in different colors, according to where it was on the horizon when each exposure was taken.
Dust devils occur on both Mars and on Earth when solar energy heats the surface, resulting in a layer of warm air just above the surface. Since the warmed air is less dense than the cooler atmosphere above it, it rises, making a swirling thermal plume that picks up the fine dust from the surface and carries it up into the atmosphere. This plume of dust moves with the local wind.
More than 650 dust devils have been recorded by Spirit since its operations began in 2004. The mission is currently in its third season of dust devils on Mars, which typically begin in Martian spring.
Scientists Discover New Black Hole 500x Larger Than The Sun
An artist's impression of HLX-1 (credit: Heidi Sagerud)
Until now, there have been two known types of black holes: stellar-mass black holes that are several times more massive than our sun and are created when really big stars die out, and supermassive black holes that are millions to billions of times the mass of the sun and which sit in the center of most, maybe all, galaxies, including our own Milky Way. While astrophysicists have been fairly certain of how the smaller black holes are created, the creation of the larger ones has been largely a mystery. The main hypothesis is that they are formed from the merger of multiple medium-size black holes. But no one had ever confirmed the existence of black holes of this size. Until this week.
A team led by scientists at the Centre d’Etude Spatiale des Rayonnements in France reports in today’s issue of Nature that they have found a black hole that is more than 500 times more massive than the sun. They found an X-ray source, now named Hyper-Luminous X-ray source 1 (HLX-1), on the edge of the galaxy ESO 243-49 that has a maximum X-ray brightness about 260 million times that of the sun. As gas falls into a black hole, energy is released, much of it in the form of X-rays. Only a medium-size black hole could create an X-ray signature that bright, the scientists say.
Oort cloud, is a postulated spherical cloud
of comets situated about 50,000 to 100,000 AU from
the Sun. This is approximately 1000 times the distance
from the Sun to Pluto or roughly one light year, almost
a quarter of the distance from the Sun to Proxima
Centauri, the star nearest the Sun. The Oort cloud
would have its inner disk at the ecliptic from the
Kuiper belt. Although no direct observations have
been made of such a cloud, it is believed to be the
source of most or all comets entering the inner solar
system (some short-period comets may come from the
Kuiper belt), based on observations of the orbits
of comets. Source: Wikipedia