THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Founded January 1970
Julian date: 2457670.16
"Reality is all very well, but it is more of a tragedy to lose
touch with fantasy."
*THE DAILY ASTRONOMER*
*Friday, October 7, 2016*
*Quiz # 6: Myths and Misconceptions*
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FIRST FRIDAY ART WALK!
Today 5:00 p.m. at the Southworth Planetarium
The "Prayers Made Visible" series continues.
Free and open to the public!
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"Myths and Misconceptions" is the topic on this afternoon's "Radio
Astronomy" radio show. WMPG 90.9 FM (www.wmpg.org)
Fridays at 1:00 p.m.
Play along with us today as we try to dispel as many
astronomical misconceptions as we can in half an hour.
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Today's glittering gem from the cave of the quiz wizard abounds with
astronomical myths and misconceptions. Unlike most quizzes that offer
answer choices, this quiz consists of various statements. Your task is to
determine if the statement is true or a misconception. The answer
section will offer more information about each statement. We advise
caution, of course, as a couple of these might be a mite tricky.
1. Looking directly at a total solar eclipse is dangerous.
2. The last quarter moon is slightly dimmer than the first quarter moon
3. Polaris, the north star, is the brightest night sky star.
4. Because of light's finite travel speed, we are not seeing the stars as
they appear now, so most of the stars we see no longer exist.
5. Astronauts aboard the International Space Station experience far less
gravity than people on Earth.
6. Comet tails always point away from the Sun.
7. When at its closest distance, Mars will appear as large as the full
moon.
8. The moon has so many craters because it has no air or water to erode
them.
9. Galileo invented the telescope
10. The moon is the only body involved in Earth's tides
ANSWERS
1. MYTH! (With a caveat)
When a solar eclipse is total, one may observe it without doing any damage
to the eyes. HOWEVER, one should be sure to know when totality will end
because one does NOT want to look at the eclipse when the first sliver of
Sun appears.
2. TRUE!
The first quarter moon is 9% as bright as the full moon, but the last
quarter moon is only 8% as bright as the full moon. The side of
the moon illuminated at first quarter is slightly brighter than the side
illuminated during the last quarter moon.
*The first quarter moon (on the left) is brighter than the *
*last quarter moon (on the right), because the part of the surface*
*illuminated during a first quarter moon is not as dark as the*
*part we see during a last quarter moon.*
3. MYTH!
Sirius, the brightest star is Canis Major, is the night sky's brightest
star. Polaris ranks 47th!
4. MYTH!
While it is true that a few stars such as Betelgeuse (Orion) and Antares
(Scorpius) are toward the end of their life cycles and might have already
gone supernova, almost all of the stars we see still exist. Even the most
distant naked eye stars will only be a few thousand light years from
Earth. Most stars have life spans far exceeding 10 million years.
5. MYTH!
The astronauts on the ISS float because they are "falling" with the station
as it revolves around Earth. The space station is about 250 miles
above the planet's surface, so the astronauts are experiencing slightly
less gravity than we do on the ground, but the difference is not
significant. The astronauts float because they are orbiting Earth within
the space station.
6. TRUE!
We think of comets as having heads with long flowing tails stretched out
behind them as they travel. In fact, this tail -which is actually two
tails*- points away from the Sun. As the comet approaches the Sun, the
tail forms behind the head. As the comet moves away from the Sun, the tail
points ahead of it. (A difficult thing to imagine, we know.)
7. MYTH!
And this myth has been promulgated through the internet for years. In
August 2003, Mars came closer to Earth than it had been in 60,000 years!
At this close approach, Mars still looked only like a bright red star.
In order for Mars to appear as large as the full moon, it would have to be
about half a million miles from Earth. Even at closest approach, Mars will
be a bit more than 30 million miles from us.
8. TRUE!
When observing the moon, one will see many craters, some of which formed
billions of years ago! The moon doesn't have air, water or weather
systems like we do on Earth. Therefore, a moon crater won't experience any
erosion as craters do on Earth.
9. MYTH!
Galileo Galilei was the first person to use a telescope to make
astronomical observations. Dutch lensmaker Hans Lippershey is created with
having invented the telescope in 1609. Of course, even this claim is
disputed. Even though Galileo revolutionized astronomy by using the
telescope for astronomy, he was not it inventor.
10. MYTH!
The moon is the most important body involved in Earth's tides. However, the
Sun is also involved, albeit it to a lesser extent. For this reason,
tides are highest around the full and new moon, the two times when the
moon, Earth and Sun are linearly aligned.
*A dust tail, formed by particles liberated from the sublimating ice, and
an ion tail repelled by the solar wind.