...han 200 years, originate in the Kuiper Belt. Halley's Comet, which returns about once every 76 years, is a short period comet.
Halley's Comet which returns about every 76 years is a short period comet from the Kuiper Belt
15 KB (2,387 words) - 03:17, 24 July 2014
<center>'''You know about ZODIAC CONSTELLATIONS'''</center>
...Iraq thousands of years ago, precession has shifted the constellations by about a month. So the constellation you were born under is probably the sign for
10 KB (1,676 words) - 23:34, 7 January 2012
'''Small stars''', up to about 1.4 solar masses, collapse to become '''white dwarfs''' while quietly sendi
...nly enough of the star remains to form a neutron star ... but if more than about 2 times the mass of the Sun remains after the explosion, it collapses to be
17 KB (2,924 words) - 00:04, 28 February 2012
...cist-explains-why-parallel-universes-may-exist Interview with Brian Greene about Fabric of the Cosmos]
...zon.com/A-Short-History-Nearly-Everything/dp/0767908171 Delightful reading about A Short History of Nearly Everything, a Book by Bill Bryson]
4 KB (604 words) - 04:06, 12 August 2017
...://prancer.physics.louisville.edu/astrowiki/index.php/Immersive_Video_Wall About the Video Room]
3 KB (443 words) - 17:22, 30 March 2017
...he charcter goes immediately after the symbol "+" so there is no ambiguity about your intent. Also, the next line has to be indented because returning to t
Now we see how integers are stored in memory, what about floating point? Fortunately, we rarely need to know the details, except th
29 KB (4,835 words) - 07:38, 22 March 2018
...n the data set, taken on the night of October 5, 2010, at about 15:50 UTC (about 1:50 AM) by Dr. Rhodes Hart. Each one is a 30 second exposure -- short by
The Tarantula Nebula is about 170,000 light years away, in another galaxy. It's as far as our telescopes
17 KB (3,096 words) - 02:12, 3 October 2015
...s. Earth goes around the Sun twice as fast as Mars, lapping the Red Planet about every two years. Both planets have elliptical orbits, so their close encoun
''3. When is the next opposition of Mars, and about how many days are there from one opposition to the next?''
15 KB (2,643 words) - 03:34, 23 October 2013
...ittle ellipse in the sky about 1/1.3 arcseconds in semimajor axis, that is about 2/1.3 arcseconds across. As you will see soon, this is a very very small an
...as exactly the measured brightness at each pixel in the image, information about how the image was recorded, and a calibration that converts the position in
13 KB (2,346 words) - 07:38, 17 November 2015
about the origin of its unusual 5000 light year long jet of electrons.</center>
...the constellation Eridanus. It is over 100,000 light years across, and is about the same size as the Milky Way. It is unusual in that while it is a classic
23 KB (3,692 words) - 07:56, 27 March 2012
...r instance, to send a satellite beyond Earth we have to give it a speed of about 11 km/s. To escape the solar system from Earth's orbit takes 42 km/s, but t
...Take all the mass of the Sun, put it inside a sphere just 3 km in radius (about 2 milies), and it would be a black hole.
14 KB (2,446 words) - 17:56, 2 April 2012
...those planets. The images of Saturn returned by the Cassini satellite take about 1 hour and 23 minutes to travel 1,300,000,000 kilometers to reach us.
or about 150 million km, 93 million miles, 8.3 light minutes.
19 KB (3,164 words) - 04:18, 6 March 2012
First, there are a few things you need to know about using Stellarium. You might look at the Stellarium [http://www.stellarium.
...he sky as it is now, and you may run the clock forward or set the time for about an hour after sunset to see the night sky for the current season. In this
19 KB (3,198 words) - 04:22, 12 August 2017
# Print information about the image
...with 16 integer data bits per pixel. The other entries provide information about the image data. Therefore in dealing with FITS data we may need to change
29 KB (4,713 words) - 19:49, 16 July 2017
...rtently use. Remember that once the projectors are powered down, there is about a 15 minute delay before you can power them up again.
...or a techinician unless you have been taught how to do it. It also takes about 45 minutes, so in this state the system probably cannot be restored for stu
10 KB (1,766 words) - 04:55, 18 September 2013
...there are over 100 million rods and 6.5 million cones in a typical retina, about 100,000 per mm2.
The telescope is 8 inches (about 20 centimeters) in diameter. In perfectly still air under
22 KB (4,196 words) - 08:13, 30 January 2013
...nearest Earth. Since Earth orbits the Sun once a year, and Mars orbits in about 1.88 earth years (687 days), Mars and Earth are near one another only once
Also, a Martian day is about 24 1/2 hours, and the planet's axis tilts 25° compared to Earth's 23° til
15 KB (2,437 words) - 23:08, 23 July 2014
...the supernova in M101 that in 25 days the supernova drops in brightness by about 1.5 magnitudes. Although we did not capture this one at its maximum, we
10 KB (1,666 words) - 02:46, 4 October 2015
First, there are a few things you need to know about using Stellarium. You might look at the Stellarium [http://www.stellarium.
.... Set your location in the software, and check that sunset occurs at about the right time.
13 KB (2,242 words) - 19:34, 2 September 2013
...ded to 0.534 seconds of arc, and most of the light is within two pixels or about 1 second of arc. That is typical of a ground-based large telescope unless i
...what the reference time was though if you are interested you can read more about "unix time" here. You can convert this number to a date and time you are u
20 KB (3,476 words) - 05:51, 12 November 2016
Before we begin, there's a necessary cautionary warning about the Sun:
...tance of 1 meter from the hole to the screen you are projecting on, a hole about 2 mm in diameter will work well. A size between 1/16th inch and 1/8th inch
11 KB (2,030 words) - 06:03, 28 January 2014
...olumn, and has one star per line. Each line contains specific information about the star, including cross-referenced catalog numbers, celestial coordinates
9 KB (1,559 words) - 21:26, 22 March 2018
Suppose that we have a catalog of data containing information about astronomical objects, and we want to find the data in the catalog that are
8 KB (1,310 words) - 05:47, 10 February 2015
...Why would you like to see this object, and what would you like to learn about it that a telescope image or measurement could reveal?
and you are encouraged to explore it to see about the observatories and their telescopes. The content is currently under deve
18 KB (3,021 words) - 21:58, 13 February 2017
Look at what is available, think about what you asked for, and decide what question you want to explore. If you d
7 KB (1,226 words) - 11:08, 19 November 2014
Saturn's axis is tipped about 27 degrees from the plane of its orbit, and most of the time we either look
For more information about the Cassini-Huygens mission, visit [http://saturn.jpl.nasa.gov http://satur
10 KB (1,544 words) - 04:30, 7 February 2012
...tory/celsius_scale.html Celsius], which is hotter than Mercury even though about twice as far from the Sun.
...imes that at [http://apod.nasa.gov/apod/ap020527.html sea-level] on Earth, about that 1km deep under the ocean. does not make it very inviting. Despite thes
16 KB (2,688 words) - 23:04, 23 January 2012
The mirror at the top inside of the tower is adjustable about a horizontal axis to provide small corrections of the image north-south. I
...ximately 40 cm in diameter on the floor below. At this size, the image is about 1/4 the brightness of direct daylight, and is an darkened corridor where it
7 KB (1,183 words) - 21:20, 30 January 2012
...e, relativity. It's the kind of relativity that Galileo and Newton thought about.
...fornia. In the laboratory its energy is about 50 billion "electron volts", about 4 billion times more energy than an electrons that come out of your car's b
18 KB (3,017 words) - 18:48, 2 April 2012
about the range of
of about 540 nm. An alternative unit is called the Angstrom, just
12 KB (2,045 words) - 03:24, 28 August 2012
...ons and the nuclei of the atoms. Yet if the star is too massive, more than about 1.4 times the Sun's mass, the pressure the electrons exert on one another i
...ust as in particle colliders at [http://public.web.cern.ch/public/en/About/About-en.html CERN] here on Earth, a machine we build to study the constituents o
7 KB (1,208 words) - 22:24, 27 February 2012
...that are close (on a cosmological scale) to the much richer Virgo Cluster. About 40 to 80 million light years away from us, in a direction not far from the
and read about it on Wikipedia:
19 KB (3,387 words) - 14:12, 5 April 2016
...arth and in space are the astronomer's primary tools to gather information about the universe. You are probably familiar with small telescopes and binocular
...ts extrordinary discoveries. It is in low orbit, circling every 96 minutes about 560 km above the Earth's surface, and beyond Earth's atmosphere. The Hubble
9 KB (1,487 words) - 21:08, 23 January 2012
an iron ball about 1 foot in diameter from a wire 67 meters (220 feet) long. The ball could ea
Find a piece of string about a meter long (a meter is 40 inches). Tie one end of it to a weight of
10 KB (1,742 words) - 00:01, 8 January 2012
...3.5 billion years, showing that the rate of impacts declined to a minimum about 400 million years ago, just when life on Earth flourished. Recently they we
...me it circles Earth. We can see by the Moon's phases that the lunar day is about 30 Earth days.
14 KB (2,354 words) - 05:37, 22 February 2012
...of galaxies. The Cosmic Background Radiation which we see today originated about 300,000 years after the beginning of time. and the regions of higher densit
After 1 year, its temperature was about that in the center of a star like the Sun, 15,000,000 K, and it was cooling
19 KB (3,169 words) - 18:22, 16 April 2012
...On this scale, the thin gas between stars may reach a temperature of only about 3 K. The Earth would be that cold too, except for some heat left over from
...anced by energy flowing out of its interior. '''Sunspots''' are cooler, at about 4500 K, because energy flow into them is blocked by a strong local magnetic
26 KB (4,226 words) - 18:46, 23 January 2012
...same. No matter how we make the measurement, we will find light moving at about 300,000 km/s. Multiply '''z''' by this speed, and you'll have that the velo
...effect has been studied with high precision. We find that galaxies recede about 70 km/sec faster for each '''megaparsec''' more distant they are. This is w
5 KB (884 words) - 17:46, 19 March 2012
...e and always the same size, since at the time Hubble had not yet found out about redshifts.
...ide the observable universe (approximately 46.5 billion light years away). About 60 million years before the end, gravity would be too weak to hold the [htt
15 KB (2,570 words) - 21:00, 9 April 2012
an insulated metal box about 15 inches on a side. A large window on the
to about -78 C. The pan is covered with
11 KB (1,899 words) - 14:18, 19 November 2013
About 20 seconds into the film, the Sun sets in the west (notice the palm
Shortly after this, about 40 seconds into the film, you see sunset again. Oddly
12 KB (2,189 words) - 19:29, 5 October 2013
The light sensitive area is the square about 1 cm on a side. It is under a protective glass cover, and attaches to the
...oss. When a photon (a light particle) arrives near one of these, there is about a 50% chance that it will excite an electron that will be trapped in the pi
16 KB (2,898 words) - 07:14, 8 March 2016
...the computer that is hosting the program, and the Internet or cloud. What about the other side, the user's perspective on computing?
...icular application. I have excerpted these from [http://www.rmi.net/~lutz/about-pp.html Programming Python by Mark Lutz (O'Reilly 2011)] which is highly re
24 KB (3,865 words) - 17:50, 2 February 2017
...f it were seen at a distance of 10 parsecs, 32 light years. To learn more about RR Lyrae stars you can read the [http://en.wikipedia.org/wiki/RR_Lyrae Wiki
16 KB (2,713 words) - 02:21, 3 October 2015
...ystem has been under development for a decade and is mature. You can read about it and even preview its capabilities on the web. Keep in mind if you decid
...docs.python.org/2/faq/windows.html "frequently asked question" (FAQ) page] about Python on Windows to help you at first, and also consult [http://docs.pytho
14 KB (2,366 words) - 06:20, 16 March 2018
...or], who follows Orion across the sky each winter night. The [http://space.about.com/od/stars/p/siriusinfo.htm brightest star] in our sky is '''Sirius''', o
...ne [http://en.wikipedia.org/wiki/Astronomical_unit astronomical unit] (AU) about 150,000,000 km or '''8 light minutes'''.
18 KB (3,104 words) - 23:06, 27 February 2012
...wiki/Earth_observation_satellite website on Wikipedia] with links to pages about them. The weather satellites are operated by many different countries and
...ed as a short duration (100 days for science) mission designed to find out about the dust that is near the Moon's surface. When that phase was over in Apri
7 KB (1,196 words) - 03:03, 24 July 2014