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Want to know the position of the Moon today? Or are you looking for some resources for the Moon tonight. The Moon is moving quickly around the Earth. This means that the time and location that the Moon will rise or set depends on your location on Earth. The phase of the Moon is always seen the same from everyone on Earth, but that changes from day to day.
To see what the Moon is doing today, you’ll want to consult our calendars of Moon phases. Just click the link for the year that you’re interested in, and then scroll down to the month.
If you’re looking for something more specific, like what the Moon looks like right now, check out this handy calculator from StarDate Online.
Do you want to find out the moonrise and moonset times from your location? Here’s a great tool, which calculates the moonrise/moonset times for the entire year based on your location.
When you see the Moon way up in the sky, it’s hard to get a sense of perspective about how big the Moon really is. Just how big is the Moon compared to Earth?
Let’s take a look at the diameter first. The diameter of the Moon is 3,474 km. Now, let’s compare this to the Earth. The diameter of the Earth is 12,742 km. This means that the Moon is approximately 27% the size of the Earth.
What about surface area? The surface area of the Moon is 37.9 million square kilometers. That sounds like a lot, but it’s actually smaller than the continent of Asia, which is only 44.4 million square km. The surface ares of the whole Earth is 510 million square km, so the area of the Moon compared to Earth is only 7.4%.
How about volume? The volume of the Moon is 21.9 billion cubic km. Again, that sounds like a huge number, but the volume of the Earth is more like 1 trillion cubic kilometers. So the volume of the Moon is only 2% compared to the volume of the Earth.
Finally, let’s take a look at mass. The mass of the Moon is 7.347 x 1022 kg. But the Earth is much more massive. The mass of the Earth is 5.97x 1024 kg. This means that the mass of the Moon is only 1.2% of the mass of the Earth. You would need 81 objects with the mass of the Moon to match the mass of the Earth.
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The volume of the Moon is about 21.9 billion cubic kilometers.
Does that sound like a lot? For comparison, the volume of the Earth is 1 trillion cubic kilometers. In other words, the volume of the Moon is only 2% the volume of the Earth.
The interior of the Moon is composed of a crust, mantle and core. Astronomers think that the lunar core is about 350 km across, and accounts for only 20% of the size of the Moon. Most other planets and moons in the Solar System have a core that accounts for about 50% of their diameter. Outside the core is the middle mantle, and this is surrounded by an upper mantle.
Colored global elevation map based on terrain data from the Kaguya orbiter Credit: Japan Aerospace Exploration Agency (JAXA)
Are you looking for a map of the Moon? As it turns out, there are plenty of resources on the internet that show the Moon’s topography, geology, and map out it’s many interesting surface features – such as craters, volcanoes, and surface rilles. These maps are the result of decade’s worth of satellite and telescopic imaging, lunar landing missions, and even manned missions to the Moon. The exploration is ongoing, and more data pours in with every passing year!
And it just so happens that we’ve compiled a list for your convenience and viewing pleasure. Below are a short collection of websites that provide comprehensive and even interactive maps of the Moon, as well as access to archival images and thousands of pictures of the surface. Click on the links and prepare to do a little exploring of your own!
Observatorio ARVAL – This map of the Moon shows the location of all the seas and major craters on the surface of the Moon.
Google Moon – This is one of the coolest tools you can use to see a lunar map. It has the locations of all the Apollo landing sites.
USGS Moon Maps – The USGS has released a series of topographical maps of the Moon, and various images returned from the Clementine and other missions. If you want data… here’s where you’ll find it.
Albedo Map of the Moon – Here are some maps of the Moon built up with 50,000 images gathered by the Clementine mission.
Maps of the Moon – A collection of mosaic, labelled, and color-coded topographic maps provided by Professor Seligman (BA Astronomy and Physics, MA Astronomy, from UCLA).
Moon-Edu – A resource collection of Moon interactive maps, images and sky-watcher/moon-watcher guides, provided by Wikispaces.
Consolidated Lunar Atlas – an online collection of Lunar resources maintained by The Lunar and Planetary Institute, a research institute that provides support services to NASA and the planetary science community.
For more information and resources about the Earth’s Moon, be sure to check out the websites of the various federal space agencies that helped contribute to our growing understanding of it. These include NASA’s Solar System Exploration, the European Space Agency’s The Moon – Our Neighbor and Destination: Moon, the Japan Aerospace Exploration Agency’s (JAXA) Lunar Exploration Program.
Welcome back to Constellation Friday! Today, in honor of the late and great Tammy Plotner, we will be dealing with “Berenice’s Hair” – the Coma Berenices constellation!
In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.
One of these is the constellation Coma Berenices, an ancient constellation located in the norther skies. In the Almagest, Ptolemy considered the asterism to be part of the constellation Leo. Today, it is one of the 88 constellations recognized by the International Astronomical Union, and is bordered by the constellations of Canes Venatici, Ursa Major, Leo, Virgo and Boötes.
Name and Meaning:
In mythology, it is easy to see why this dim collection of stars was once associated with Leo and considered to be the tuft of hair at the end of the Lion’s tail. However, as the years passed, a charming legend grew around this sparkling group of stars. Since the time of Ptolemy, this grouping of stars was recognized and although he didn’t list it as one of his 88 constellations, he did refer to is as “Berenice’s Hair”.
Coma Berenices as seen by the naked eye. Credit: Till Credner/ AlltheSky.com
As legend would have it, the good Queen Berenice II of Egypt offered to sacrifice her beautiful long hair to Aphrodite for the safe return of her husband from battle. When she cut off her locks and placed it on the altar and returned the next day, her sacrifice was gone. To save his life, the court astronomer proclaimed Aphrodite had immortalized Berenice’s gift in the stars… and thus the Lion lost his tail and the astronomer saved his hide!
History of Observation:
Like many of the 48 constellations recognized by Ptolemy, Coma Berenices traces it routes back to ancient Mesopotamia. To Babylonian astronomers, it was known as Hegala, which translated to “which is before it”. However, the first recorded mention comes from Conon of Samos, the 3rd century BCE court astronomer to Ptolemy III Euergetes – the Greek-Egyptian king. It was named in honor of his consort, Berenice II, who is said to have cut off her long hair as a sacrifice to ensure the safety of the king.
The constellation was named “bostrukhon Berenikes” in Greek, which translates in Latin to “Coma Berenices” (or “Berenice’s hair”). Though it was previously designated as its own constellation, Ptolemy considered it part of Leo in his 2nd century CE tract the Almagest, where he called it “Plokamos” (Greek for “braid”). The constellation was also recognized by many non-western cultures.
In Chinese astronomy, the stars making up Coma Berenices belonged to two different areas – the Supreme Palace Enclosure and the Azure Dragon of the East. Eighteen of the constellation’s stars were in an area known as Lang wei (“seat of the general”). To Arabic astronomers, Coma Berenices was known as Al-Du’aba, Al Dafira and Al-Hulba, forming the tuft of the constellation Leo (consistent with Ptolemy’s designation).
Fragment of Mercator’s 1551 celestial globe, showing Coma Berenices. Credit: Harvard Map Collection
By the 16th century, the constellation began to be featured on globes and maps produced by famed cartographers and astronomers. In 1602, Tycho Brahe recognized it as its own constellation and included it in his star catalogue. In the following year, it was included in Johann Bayer’s famed celestial map, Uranometria. In 1920, it was included by the IAU in the list of the 88 modern constellations.
Notable Objects:
Despite being rather dim, Coma Berenices is significant because it contains the location of the North Galactic Pole. It is comprised of only 3 main stars, but contains 44 Bayer/Flamsteed designated members. Of its main stars, Alpha Comae Berenices (aka. Diadem) is the second-brightest in the constellation.
The name is derived from the Greek word diádema, which means “band” or “fillet”, and represents the gem in Queen Berenice’s crown. It is sometimes known by its other traditional name, Al-Zafirah, which is Arabic for “the braid”. It is a binary star composed of two main sequence F5V stars that are at a distance of 63 light years from Earth.
The Black Eye Galaxy (Messier 64). Credit: NASA/The Hubble Heritage Team (AURA, STScI)
It’s brightest star, Beta Comae Berenices, is located 29.78 light years from Earth and is a main sequence dwarf that is similar to our Sun (though larger and brighter). It’s third major star, Gamma Comae Berenices, is a giant star belonging to the spectral class K1II and located about 170 light years from Earth.
Coma Berenices is also home to several Deep Sky Objects, which include spiral galaxy Messier 64. Also known as the Black Eye Galaxy (Sleeping Beauty Galaxy and Evil Eye Galaxy), this galaxy is located approximately 24 million light years from Earth. This galaxy has a bright nucleus and a dark band of dust in front of it, hence the nicknames.
Then there is the Needle Galaxy, which lies directly above the North Galactic Pole and was discovered by Sir William Herschel in 1785. It is one of the most famous galaxies in the sky that can be viewed edge-on. It lies at a distance of about 42.7 million light years from Earth and is believed to be a barred spiral galaxy from its appearance.
Coma Berenices is also home to two prominent galaxy clusters. These includes the Coma Cluster, which is made up of about 1000 large galaxies and 30,000 smaller ones that are located between 230 and 300 million light years from Earth. South of the Coma Cluster is the northern part of the Virgo Cluster, which is located roughly 60 million light years from Earth.
The globular cluster Messier 53 (NGC 5024), located in the Coma Berenices constellation. Credit: NASA (Wikisky)
Other Messier Objects include M53, a globular cluster located approximately 58,000 light years away; Messier 100, a grand design spiral galaxy that is one of the brightest members of the Virgo cluster (located 55 million light years away); and Messier 88 and 99 – a spiral galaxy and unbarred spiral galaxy that are 47 million and 50.2 million light years distant, respectively.
Finding Coma Berenices:
Coma Berenices is best visible at latitudes between +90° and -70° during culmination in the month of May. There is one meteor shower associated with the constellation of Coma Berenices – the Coma Berenicid Meteor shower which peaks on or near January 18 of each year. Its fall rate is very slow – only one or two per hour on average, but these are among the fastest meteors known with speeds of up to 65 kilometers per second!
For both binoculars and telescopes, Coma Berenices is a wonderland of objects to be enjoyed. Turn your attention first to the brightest of all its stars – Beta Coma Berenices. Positioned about 30 light years from Earth and very similar to our own Sun, Beta is one of the few stars for which we have a measured solar activity period – 16.6 years – and may have a secondary activity cycle of 9.6 years.
Now look at slightly dimmer Alpha. Its name is Diadem – the Crown. Here we have a binary star of equal magnitudes located about 65 light years from our solar system, but it’s seen nearly “edge-on” from the Earth. This means the two stars appear to move back-and-forth in a straight line with a maximum separation of only 0.7 arcsec and will require a large aperture telescope with good resolving power to pull them apart. If you do manage, you’re separating two components that are about the distance of Saturn from the Sun!
The location of the northern constellation Coma Berenices. Credit: IAU/Sky&Telescope magazine
Another interesting aspect about singular stars in Coma Berenices is that there are over 200 variable stars in the constellation. While most of them are very obscure and don’t go through radical changes, there is one called FK Comae Berenices which is a prototype of its class. It is believed that the variability of FK Com stars is caused by large, cool spots on the rotating surfaces of the stars – mega sunspots! If you’d like to keep track of a variable star that has notable changes, try FS Comae Berenices (RA 13 3 56 Dec +22 53 2). It is a semi-regular variable that varies between 5.3m and 6.1 magnitude over a period of 58 days.
For your eyes, binoculars or a rich field telescope, be sure to take in the massive open cluster Melotte 111. This spangly cloud of stars is usually the asterism we refer to as the “Queen’s Hair” and the area is fascinating in binoculars. Covering almost 5 full degrees of sky, it’s larger than most binocular fields, but wasn’t recognized as a true physical stellar association until studied by R.J. Trumpler in 1938.
Located about 288 light years from our Earth, Melotte 111 is neither approaching nor receding… unusual – but true. At around 400 million years old, you won’t find any stars dimmer than 10.5 magnitude here. Why? Chances are the cluster’s low mass couldn’t prevent them from escaping long ago…
Now turn your attention towards rich globular cluster, Messier 53. Achievable in both binoculars and small telescopes, M53 is easily found about a degree northwest Alpha Comae. At 60,000 light years away from the galactic center, it’s one of the furthest globular clusters away from where it should be. It was first discovered by Johann Bode in 1755, and once you glimpse its compact core you’ll be anxious to try to resolve it.
The Needle Galaxy (NGC 4565). Credit: ESO
With a large telescope, you’ll notice about a degree further to the east another globular cluster – NGC 5053 – which is also about the same physical distance away. If you study this pair, you’ll notice a distinct difference in concentrations. The two are very much physically related to one another, yet the densities are radically different!
Staying with binoculars and small telescopes, try your hand at Messier 64 – the “Blackeye Galaxy”. You’ll find it located about one degree east/northeast of 35 Comae. While it will be nothing more than a hazy patch in binoculars, smaller telescopes will easily reveal the signature dustlane that makes M64 resemble its nickname. It is one of the brightest spiral galaxies visible from the Milky Way and the dark dust lane was first described by Sir William Herschel who compared it to a “Black Eye.”
Now put your telescope on Messier 100 – a beautiful example of a grand-design spiral galaxy, and one of the brightest galaxies in the Virgo Cluster. This one is very much like our own Milky Way galaxy and tilted face-on, so we may examine the spiral galaxy structure. Look for two well resolved spiral arms where young, hot and massive stars formed recently from density perturbations caused by interactions with neighboring galaxies. Under good observing conditions, inner spiral structure can even be seen!
Try lenticular galaxy Messier 85. In larger telescopes you will also see it accompanied by small barred spiral NGC 4394 as well. Both galaxies are receding at about 700 km/sec, and they may form a physical galaxy pair. How about Messier 88? It’s also one of the brighter spiral galaxies in the Virgo galaxy cluster and in a larger telescope it looks very similar to the Andromeda galaxy – only smaller.
How about barred spiral galaxy M91? It’s one of the faintest of the Messier Catalog Objects. Although it is difficult in a smaller telescope, its central bar is very strong in larger aperture. Care to try Messier 98? It is a grand edge-on galaxy and may or may not be a true member of the Virgo group. Perhaps spiral galaxy Messier 99 is more to your liking… It’s also another beautiful face-on presentation with grand spiral arms and a sweeping design that will keep you at the eyepiece all night!
There are other myriad open clusters and just as many galaxies waiting to be explored in Coma Berenices! It’s a fine region. Grab a good star chart and put a pot of coffee on to brew. Comb the Queen’s Hair for every last star. She’s worth it.
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Moonrise is the first appearance of the Moon over the Earth’s horizon.
Unlike the Sun, the rising of the Moon changes from day to day and location to location because the Moon is orbiting the Earth. The Moon takes just over 27 days to complete an orbit around the Earth, so you can actually trace its movement in the sky from hour to hour. This is why a lunar eclipse only lasts a few hours. That’s how long it takes for the Moon to pass through the Earth’s shadow.
The movement of the Moon comes from both the rotation of the Earth – which makes the Sun and the stars move through the sky, as well as the orbital speed of the Moon.
Where and when the Moon rise depends on your location on Earth. So you can’t just see a generic table of moon rise times.
Fortunately, the Internet comes to the rescue. Here are some links to some calculators that will help you find out what time the Moon will rise in your specific location.
Moonrise and Moonset at Specified Location (NASA) – This calculator lets you punch in your specific latitude and longitude, year and month and then see a table of times that the Moon will rise and set for your location.
Farmer’s Almanac – The Farmer’s Almanac website has a tool that lets you put in your ZIP or Postal Code and date and then see a list of moonrise and sunrise times. You can also browse by city. This is better if you don’t know your latitude and longitude.
US Naval Observatory – This website lets you retrieve moonrise/sunrise time table for an entire year.
We have written many articles about the Moon on Universe Today. Here’s a story about building a moon base.
Astronaut Eugene Cernan from Apollo 17, the last mission to the Moon (NASA)
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Your weight on the Moon is 16.5% what you would experience on Earth. In other words, if you weighed 100 kg on Earth, you would weigh a mere 16.5 kg on the Moon. For you imperial folks, imagine you tipped the scales at 200 pounds. Your weight on the Moon would only be 33 pounds.
Why is your weight on the Moon so much less than your weight on the Earth? It’s because of the lower gravity on the Moon. Objects on the surface of the Moon experience only 16.5% of the gravity they would experience on Earth. And why does the Moon have such a lower gravity? Gravity comes from mass. The more stuff you have, the more you’ll pull with gravity.
The mass of the Moon is only 1.2% the mass of the Earth, so you might expect it to have only 1.2% of the gravity. But it’s only 27% of the size of the Earth, so when you’re standing on the surface of the Moon, you’re much closer to its center of gravity.
Because your weight on the Moon is about 1/6th your weight on Earth, but your muscles are still as strong, you could do some amazing things. You would be able to jump 6 times higher, or jump off the roof of a house and be unharmed. And here’s the coolest thing. Strap on a pair of wings inside an air-filled dome on the Moon, and you would be able to fly around with just your own muscle power.
A lunar month takes 29.53 days. This is the amount of time it takes for the Moon to complete a cycle through all the phases, from new moon to full moon and then back to new moon again. This is very close to the length of a month in the Western calendar, which usually have 30 or 31 days. Every month usually has one of each of the phases. So a typical month will have a new moon, first quarter, full moon and last quarter moon. But every now and then, a month will have two of the same phases. When a month has two full moons, the second one is called a “blue moon”.
Blue moons are rare, and that’s where the phrase comes from, “once in a blue moon”. How rare? They always happen once every 2-3 years (2.72 years, to be exact). It’s this second moon in the month that’s considered the blue moon.
Does the blue moon actually turn blue? No. A blue moon is exactly the same color as a regular full moon – yellow.
The Moon can turn blue when there’s a certain amount of dust or pollution in the air. The extra dust scatters blue light, making the Moon appear more blue. For example, the Moon appeared blue across the entire Earth for about 2 years after the eruption of Krakatoa in 1883.
Here is a list of upcoming blue moons:
2018: January 2, January 31st
2018: March 2, March 31st
2020: October 1, October 31st
We have an article here on Universe Today about all the phases of the Moon.
The moon in its waning gibbous phase on Sept. 12, 2014. Photo taken with a Canon 700D attached to a Maksutov 127mm telescope. Credit: Sarah&Simon Fisher
Human beings have been observing the Moon for as long as they have walked the Earth. Throughout recorded and pre-recorded history, they have paid close attention to its phases and accorded them particular significance. This has played a major role in shaping the mythological and astrological traditions of every known culture.
With the birth of astronomy as a scientific discipline, how the Moon appears in the night sky (and sometimes during the day) has also gone long way towards helping us to understand how our Solar System works. It all comes down to the Lunar Cycle, the two key parts of this cycle involve the “waxing and waning” of the Moon. But what exactly does this mean?-day
Lunar Cycle:
First, we need to consider the orbital parameters of the Earth’s only satellite. For starters, since the Moon orbits Earth, and Earth orbits the Sun, the Moon is always half illuminated by the latter. But from our perspective here on Earth, which part of the Moon is illuminated – and the amount to which it is illuminated – changes over time.
When the Sun, the Moon and Earth are perfectly lined up, the angle between the Sun and the Moon is 0-degrees. At this point, the side of the Moon facing the Sun is fully illuminated, and the side facing the Earth is enshrouded in darkness. We call this a New Moon.
After this, the phase of the Moon changes, because the angle between the Moon and the Sun is increasing from our perspective. A week after a New Moon, and the Moon and Sun are separated by 90-degrees, which effects what we will see. And then, when the Moon and Sun are on opposite sides of the Earth, they’re at 180-degrees – which corresponds to a Full Moon.
Waxing vs. Waning:
The period in which a Moon will go from a New Moon to a Full Moon and back again is known as “Lunar Month”. One of these lasts 28 days, and encompasses what are known as “waxing” and “waning” Moons. During the former period, the Moon brightens and its angle relative to the Sun and Earth increases.
Synthetic view of the waxing Moon as viewed from Earth on 2013-10-15 17:00:00 UTC. Credit: NASA/GSFC/Arizona State UniversityWhen the Moon starts to decrease its angle again, going from 180-degrees back down to 0-degrees, astronomers say that it’s a waning moon. In other words, when the Moon is waning, it will have less and less illumination every night until it’s a New Moon.
Waning Phases:
When the Moon is no longer full, but it hasn’t reached a quarter moon – i.e. when it’s half illuminated from our perspective – we say that it’s a Waning Gibbous Moon. This is the exact reverse of a Waxing Gibbous Moon, when the Moon is increasing in brightness from a New Moon to a Full Moon.
This is followed by a Third Quarter (or last quarter) Moon. During this period, 50% of the Moon’s disc will be illuminated (left side in the northern hemisphere, and the right in the southern), which is the opposite of how it would appear during a First Quarter. These phases are often referred to as a “Half Moon”, since half the disc is illuminated at the time.
The moon in its waning gibbous phase on Sept. 12, 2014. Photo taken with a Canon 700D attached to a Maksutov 127mm telescope. Credit: Sarah&Simon Fisher
Finally, a Waning Crescent is when the Moon appears as a sliver in the night sky, where between 49–1% of one side is illuminated after a Full Moon (again, left in the northern hemisphere, right in the southern). This is the opposite of a Waxing Crescent, when 1-49% of the other wide is illuminated before it reaches a Full Moon.
Even today, thousands of years later, human beings still look up at the Moon and are inspired by what they see. Not only have we explored Earth’s only satellite with robotic missions, but even crewed missions have been there and taken samples directly from the surface. And yet, it still possesses enough mystery to keep us inspired and guessing.
Quarter Moon, captured by NASA astronauts. Image credit: NASA
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A quarter moon occurs when we see the Moon half illuminated by the Sun, and half enshrouded in darkness. Since the illuminated side points towards the Sun, it tells astronomers that the Moon and the Sun are separated by 90-degrees from our perspective here on Earth.
You can have a first quarter moon, when the Moon is halfway between a new moon and full moon. A new moon occurs when the Moon is directly in between the Sun and the Earth. From that perspective, the illuminated Moon is facing away from the Earth. A full moon happens when the Moon and the Sun are on opposite sides of the Earth. At that point, we see the Moon fully illuminated by light from the Sun.
When we see the first quarter of the Moon, that means the amount of the Moon that’s illuminated is increasing. Astronomers call an increasingly illuminated moon: “waxing”.
You can also get a last quarter moon, when the Moon is half illuminated, but the opposite side is illuminated. This is the halfway point between a full moon and a new moon. When the amount of the Moon that’s illuminated is decreasing, astronomers call this “waning”.
Want to know when the next quarter moons are going to happen? Here’s a chart from NASA that calculates the phases of the Moon over a 6000 year period. And here’s a cool calculator that shows you what the Moon is doing right now.
![Synthetic view of the waxing Moon as viewed from Earth on 2013-10-15 17:00:00 UTC [NASA/GSFC/Arizona State University].](https://www.universetoday.com/wp-content/uploads/2013/10/tuesday_syntheticview_thumb.png)
