America's First Spaceship: Project Mercury (Infographic)
The Mercury space capsule was NASA's first manned spaceship and
launched the first Americans into orbit in the early 1960s. The
one-person spacecraft was used in three suborbital flights and three
orbital flights before being replaced by the two-person Gemini capsules.
See how the Mercury capsule worked in the SPACE.com Infographic above.
Inside Earth's Moon
Selasa, 10 April 2012
How Planets in Alien Solar Systems Stack Up (Infographic)
Venus, Second Planet from the Sun, Brightest
Planet in Solar System
Venus's History & Naming Venus, the second planet from the Sun, is named for
the ancient Roman goddess of love and beauty. The planet — the only
planet named after a female — may have been named
for the most beautiful deity of her pantheon because it shone the
brightest of the five planets known to ancient astronomers.
In ancient times, Venus was once thought to be
two different stars, the evening
star and the morning
star — that is, the ones that first appeared at sunset and sunrise.
In Latin, they were respectively known as Vesper and Lucifer.
In Christian times, Lucifer, or "light-bringer," became known as the
name of Satan before his fall. Physical Characteristics of the Planet Venus Venus and Earth are often called twins
because they are similar
in size, mass, density, composition and gravity. However, the
similarities end there. [Photos
of Venus, the Mysterious Planet Next Door]
Venus is the
hottest world in the solar system. Although Venus is not the planet
closest to the sun, its dense atmosphere traps heat in a runaway version
of the greenhouse effect that warms up the Earth. As a result, temperatures
on Venus reach 870 degrees F (465 degrees C), more than hot enough
to melt lead. Probes that scientists have landed there have survived
only a few hours before
getting destroyed.
Venus has a hellish atmosphere as well, consisting mainly
of carbon dioxide with clouds of sulfuric acid, and scientists have
only detected trace amounts of water in the atmosphere. The atmosphere
is heavier
than that of any other planet, leading to a surface pressure 90
times that of Earth.
Venus' southern hemisphere, as seen in the ultraviolet. CREDIT: ESA
The surface of Venus is extremely dry. There is no liquid
water on its surface because the scorching heat would cause any to
boil away. Roughly two-thirds percent of the Venusian surface is covered by
flat, smooth plains that are marred by thousands of
volcanoes, ranging from about 0.5 to 150 miles (0.8 to 240
kilometers) wide, with lava flows carving long, winding canals up to
more than 3,000 miles (5,000 kilometers) in length, longer than on
any other planet.
Six mountainous
regions make up about one-third percent of the Venusian surface.
One mountain range, called Maxwell, is about 540 miles (870 kilometers)
long and reaches up to some 7 miles (11.3 kilometers) high, making it
the highest feature on the planet.
Venus also possesses a number of surface features unlike
anything on the Earth. For example, Venus has coronae, or
crowns — ringlike structures that range from roughly 95 to 360 miles
(155 to 580 kilometers) wide. Scientists believe these formed when hot
material beneath the crust rises up, warping the planet’s surface. Venus
also has tesserae,
or tiles — raised areas in which many ridges and valleys have
formed in different directions.
Not only are conditions on Venus infernal, an ancient name for Venus
was even Lucifer. This name did not carry any fiendish connotations,
however — Lucifer means "light-bringer," and when seen from Earth, Venus
is brighter
than any other planet or even any star in the night sky because of
its highly
reflective clouds and its closeness to our planet.
Venus takes 243 Earth days to rotate on its axis, by far the slowest of
any of the major planets, and because
of this sluggish spin, its metal core cannot generate a magnetic
field similar to Earth's.
Venus's Orbital Characteristics
If viewed from above, while most planets rotate the same way on their
axes, Venus rotates the opposite way. While on Earth, the sun appears to
rise in the east and set in the west, if
on Venus, the sun would rise in the west and set in the east.[Venus
Transit Of 2004: 51 Photos Of Rare Celestial Sight]
The Venusian year — the time it takes to orbit the sun — is about 225
Earth days long. At the same time, it takes Venus 243 Earth days to
rotate on its axis, which normally would mean that days on Venus would
be longer than years. However, because of Venus' curious retrograde
rotation, the time from one sunrise to the next is only
about 117 Earth days long. Composition & Structure
Venus magnetic field is 0.000015 times that of Earth's field.
Internal structure
Venus' metallic
iron core is roughly 2,400 miles (6,000 kilometers) wide.
Venus' molten
rocky mantle is roughly
1,200 miles (3,000 kilometers) thick.
Venus' crust is mostly basalt, and is estimated
to be six to 12 miles (10 to 20 kilometers) thick on average. Orbit & Rotation
Average Distance from the Sun
English: 67,237,910 miles
Metric: 108,208,930 km
By Comparison: 0.723 times that of Earth
Perihelion (closest)
English: 66,782,000 miles
Metric: 107,476,000 km
By Comparison: 0.730 times that of Earth
Aphelion (farthest)
English: 67,693,000 miles
Metric: 108,942,000 km
By Comparison: 0.716 times that of Earth
(Source: NASA)
Venus's Climate
The very top layer of Venus' clouds zip around the planet every four
Earth days, propelled
by hurricane-force winds traveling roughly 224 miles (360
kilometers) per hour. This super-rotation of the planet's atmosphere,
some 60 times faster than Venus itself rotates, may be one of Venus'
biggest mysteries. The winds at the planet's surface are much slower,
estimated to be just a few miles per hour.
The Venus Express spacecraft the European
Space Agency launched in 2005 intriguingly found evidence
of lightning on the planet. This lightning is unique from that
found on the other planets in the solar system that possess it, in that
it is the only lightning known that is not associated with water clouds.
Instead, on Venus, the lightning is associated with clouds of sulfuric
acid. Scientists are excited by these electrical discharges, because
they can break molecules into fragments that can then combine with other
fragments in unexpected ways.
Unusual stripes in the upper clouds of Venus are dubbed "blue
absorbers" or "ultraviolet
absorbers" because they strongly absorb light in the blue
and ultraviolet wavelengths. These are soaking up a huge amount of
energy — nearly half of the total solar energy the planet absorbs. As
such, they seem to play a major role in keeping Venus as hellish as it
is. Their exact composition remains uncertain. Venus's Moons or Rings
Venus has no moons or rings. Research & Exploration
The United States, Soviet Union, and European
Space Agencyhave deployed many
spacecraft to Venus, more than 20 in all so far. NASA's
Mariner 2 came within 21,600 miles (34,760 kilometers) of Venus
in 1962, making it the first
planet to be observed by a passing spacecraft. The Soviet Union's Venera
7 was the first spacecraft to land on another planet, and Venera
9 which returned the first photographs of the Venusian
surface. The first Venusian orbiter, NASA's Magellan,
generated maps of 98 percent of the planet's surface using radar,
showing details of features as small as 330 feet (100 meters) across.
The European Space Agency's Venus Express is now in orbit around Venus
with a large variety of instruments, and has
confirmed the presence of lightning there. The next
mission to Venus, Japan's Akatsuki, was launched
in 2010, and will follow Venus' thick cloud layers as they are whipped
around the planet by hurricane-force winds.
Senin, 09 April 2012
Amazing Photo Captures Robot Cargo Ship's Space Station Arrival
The European Space Agency's Automated Transfer Vehicle-3
(ATV-3) approaches the International Space Station on March 28, 2012. CREDIT: NASA
Astronauts aboard the International Space Station captured an
extraordinary photo of an unmanned European cargo ship as it docked to
the orbiting outpost last week.
The European Space Agency's third Automated Transfer Vehicle (ATV-3)
launched into orbit on March 23, and arrived
at the space station five days later, on March 28. The robotic
cargo ship delivered about 7 tons of supplies, including water, oxygen,
food, clothing, experiments and propellant.
The robotic
ATV vehicles are designed to automatically dock to the space
station. In this photo, the ATV-3 is approaching its parking spot at the
Zvezda service module on the Russian segment of the orbiting complex.
The photo shows the ATV-3's
distinctive x-wing solar arrays bathed in light from the
spacecraft's sophisticated laser guidance system. The starry night sky
and the glow of lights from Earth below make up the remarkable backdrop,
as the two vehicles fly 240 miles (386 kilometers) above the planet.
Sabtu, 07 April 2012
Planetary Science Takes a Hit in 2013 (Infographic)
Ross Toro, SPACE.com Contributor
Date: 13 February 2012 Time: 06:37 PM ET
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President Barack Obama unveiled his proposed federal budget for 2013
today (Feb. 13), which includes $17.7 billion for NASA and requires
painful cuts to the agency's Mars exploration plans that are already
drawing criticism from astronomers. NASA's portion of the proposed
2013 budget features a cut on planetary science missions, but
includes some funding boosts for space technology and human exploration.
See how planetary science fares in 2013 for NASA in the above SPACE.com
infographic.
A Galaxy Full of Alien Planets (Infographic)
The latest study on the likely distribution of planets in our galaxy
has found that at least 160 billion alien worlds exist in our Milky Way.
Astronomers say the survey, based on estimates and computer projects,
means that at least 1.6 planets circle each star in our galaxy. See how
the alien planet population of our galaxy stacks up in the SPACE.com
infographic above.