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Investigative links appear above... FRJ
| See the Incredible Shrinking Planet this February Mercury makes a rare appearance in the evening sky this week. NASA states the anomalies thought to be ice on Mercury "could be something else entirely". |
February 21, 2006: It's not every
day you get to see a shrinking
planet. Today could be the day.
Step outside this evening at sunset
and look west toward the glow of
the setting sun. As the sky fades to
black, a bright planet will emerge.
It's Mercury, first planet from the
sun, also known as the "Incredible
Shrinking Planet."
day you get to see a shrinking
planet. Today could be the day.
Step outside this evening at sunset
and look west toward the glow of
the setting sun. As the sky fades to
black, a bright planet will emerge.
It's Mercury, first planet from the
sun, also known as the "Incredible
Shrinking Planet."
"This is only the second time in my life I've seen Mercury," says sky watcher Jeffrey Beall
who snapped this picture looking west from his balcony in Denver, Colorado.
who snapped this picture looking west from his balcony in Denver, Colorado.
When you see Mercury popping out of the evening
twilight, you're looking at a very strange place.
"Shrinking" is a good example:
Color enhanced photo of Mercury on right
n 1974, NASA's Mariner 10 spacecraft flew by
Mercury and, for the first time, photographed the
planet from close range. Cameras revealed a
densely cratered world—with wrinkles. Planetary
geologists call them "lobate scarps" and, like
wrinkles on a raisin, they are thought to be a sign of
shrinking. What would make a planet shrink? One
possibility: Mercury's oversized iron core has been
cooling for billions of years, and its contraction may
be the driving force behind the wrinkles...
An artificial satellite? FRJ "No one knows for sure".
twilight, you're looking at a very strange place.
"Shrinking" is a good example:
Color enhanced photo of Mercury on right
n 1974, NASA's Mariner 10 spacecraft flew by
Mercury and, for the first time, photographed the
planet from close range. Cameras revealed a
densely cratered world—with wrinkles. Planetary
geologists call them "lobate scarps" and, like
wrinkles on a raisin, they are thought to be a sign of
shrinking. What would make a planet shrink? One
possibility: Mercury's oversized iron core has been
cooling for billions of years, and its contraction may
be the driving force behind the wrinkles...
An artificial satellite? FRJ "No one knows for sure".
No one knows
because Mercury
has hardly been
explored. Only
one spacecraft
has ever been
there, and during
its oh-so-brief visit
Mariner 10
managed to
photograph less
than half (45%) of
Mercury's surface:
image. The
majority is terra
incognita.
Picture on left was
taken by Mariner
10 in 1974
because Mercury
has hardly been
explored. Only
one spacecraft
has ever been
there, and during
its oh-so-brief visit
Mariner 10
managed to
photograph less
than half (45%) of
Mercury's surface:
image. The
majority is terra
incognita.
Picture on left was
taken by Mariner
10 in 1974
What does the unknown half of
Mercury look like? Is the planet
really shrinking? Can ice stay
frozen in an inferno? Mercury
poses many questions: list. A new
NASA probe named {what else}
"MESSENGER" is en route to find
some answers, but it will not reach
Mercury until 2008.
For now, one can only peer into
the twilight and wonder. Give it a
try, this evening.
Cosmic Conjunction
Five planets - Mercury, Venus,
Mars, Jupiter and Saturn - gather
over the ancient Stonehenge
monument in England.
Image Copyright: Philip Perkins
Mercury look like? Is the planet
really shrinking? Can ice stay
frozen in an inferno? Mercury
poses many questions: list. A new
NASA probe named {what else}
"MESSENGER" is en route to find
some answers, but it will not reach
Mercury until 2008.
For now, one can only peer into
the twilight and wonder. Give it a
try, this evening.
Cosmic Conjunction
Five planets - Mercury, Venus,
Mars, Jupiter and Saturn - gather
over the ancient Stonehenge
monument in England.
Image Copyright: Philip Perkins
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As updates become available we will present them here. Frank Riccardi Director, Eyepod.Org/usassociates.us
Photo Above; Mercury is the bright "star" just above the
mountain ridge, rivaling the city lights.
Mercury is elusive because it spends most of its time
hidden by the glare of the sun. This week is different.
From now until about March 1st, Mercury moves out of
the glare and into plain view. It's not that Mercury is
genuinely farther from the sun. It just looks that way
because of the Earth-sun-Mercury geometry in late
February. A picture is worth a thousand words...
{See diagram on left}
Friday, Feb. 24th, is the best day to look that's the date
of greatest elongation or separation from the sun. Other
dates of note are Feb 28th and March 1st when the
crescent moon glides by Mercury—very pretty.
mountain ridge, rivaling the city lights.
Mercury is elusive because it spends most of its time
hidden by the glare of the sun. This week is different.
From now until about March 1st, Mercury moves out of
the glare and into plain view. It's not that Mercury is
genuinely farther from the sun. It just looks that way
because of the Earth-sun-Mercury geometry in late
February. A picture is worth a thousand words...
{See diagram on left}
Friday, Feb. 24th, is the best day to look that's the date
of greatest elongation or separation from the sun. Other
dates of note are Feb 28th and March 1st when the
crescent moon glides by Mercury—very pretty.
Left; Arecibo radar images of
north polar craters on Mercury.
Another puzzle is the
mystery-substance at Mercury's
poles. Radio astronomers have
pinged Mercury from afar using
radars on Earth, and they have
found something very bright in
Mercury's polar craters. Again,
no one knows what it is, although
a favorite possibility is ice. Frozen
water is a good reflector of radio
waves and would explain the
observations nicely.
How could frozen water exist on
Mercury? The sun heats the
planet's surface to 400 °C (750
°F) or more, too hot for frozen
anything. Yet deep down in some
polar craters, researchers
believe, the sun never shines. In
permanent shadow, the
temperature drops below -212º C
(-350° F). Suppose a piece of an
icy comet or meteorite landed in
such a crater; some of the ice
might survive. And this is the
quote from NASA...
"Or it could be something else
entirely".
north polar craters on Mercury.
Another puzzle is the
mystery-substance at Mercury's
poles. Radio astronomers have
pinged Mercury from afar using
radars on Earth, and they have
found something very bright in
Mercury's polar craters. Again,
no one knows what it is, although
a favorite possibility is ice. Frozen
water is a good reflector of radio
waves and would explain the
observations nicely.
How could frozen water exist on
Mercury? The sun heats the
planet's surface to 400 °C (750
°F) or more, too hot for frozen
anything. Yet deep down in some
polar craters, researchers
believe, the sun never shines. In
permanent shadow, the
temperature drops below -212º C
(-350° F). Suppose a piece of an
icy comet or meteorite landed in
such a crater; some of the ice
might survive. And this is the
quote from NASA...
"Or it could be something else
entirely".
