Introduction
In our entire solar system, the only object that shines with its own light is the Sun. That light always beams onto Earth and Moon from the direction of the Sun, illuminating half of our planet in its orbit and reflecting off the surface of the Moon to create moonlight.
Like Earth, the Moon has a day side and a night side, which change as the Moon rotates. The Sun always illuminates half of the Moon while the other half remains dark, but how much we are able to see of that illuminated half changes as the Moon travels through its orbit.
Current Moon Phase
Lets take a look at the individual phases, and how the movements of the Moon and Sun appear to us as we watch from the Northern Hemisphere on Earth:
New Moon
This is the invisible phase of the Moon, with the illuminated side of the Moon facing the Sun and the night side facing Earth. In this phase, the Moon is in the same part of the sky as the Sun and rises and sets with the Sun. Not only is the illuminated side facing away from the Earth, its also up during the day! Remember, in this phase, the Moon doesnt usually pass directly between Earth and the Sun, due to the inclination of the Moons orbit. It only passes near the Sun from our perspective on Earth.
Waxing Crescent
This silver sliver of a Moon occurs when the illuminated half of the Moon faces mostly away from Earth, with only a tiny portion visible to us from our planet. It grows daily as the Moons orbit carries the Moons dayside farther into view. Every day, the Moon rises a little bit later.
First Quarter
The Moon is now a quarter of the way through its monthly journey and you see half of its illuminated side. People may casually call this a half moon, but remember, thats not really what youre witnessing in the sky. Youre seeing just a slice of the entire Moon half of the illuminated half. A first quarter moon rises around noon and sets around midnight. Its high in the sky in the evening and makes for excellent viewing.
Waxing Gibbous
Now most of the Moons dayside has come into view, and the Moon appears brighter in the sky.
Full Moon
This is as close as we come to seeing the Suns illumination of the entire day side of the Moon (so, technically, this would be the real half moon). The Moon is opposite the Sun, as viewed from Earth, revealing the Moons dayside. A full moon rises around sunset and sets around sunrise. The Moon will appear full for a couple of days before it moves into
Waning Gibbous
As the Moon begins its journey back toward the Sun, the opposite side of the Moon now reflects the Moons light. The lighted side appears to shrink, but the Moons orbit is simply carrying it out of view from our perspective. The Moon rises later and later each night.
Last Quarter
The Moon looks like its half illuminated from the perspective of Earth, but really youre seeing half of the half of the Moon thats illuminated by the Sun or a quarter. A last quarter moon, also known as a third quarter moon, rises around midnight and sets around noon.
Waning Crescent
The Moon is nearly back to the point in its orbit where its dayside directly faces the Sun, and all that we see from our perspective is a thin curve.
When we think of the way the Moon seems to change over the course of a month, we think of phases. But frequent Moon observers know that the Moon also appears to twist, nod, and roll slightly during its journey across the sky, allowing us to peek around the Moon's shoulder and catch glimpses of the farside. This phenomenon is called libration.
Because the Moon's orbit is not perfectly circular, its distance from Earth and its speed in orbit both change slightly throughout the month. The Moons rate of rotation around its own axis, though, always stays the same.
When the Moon is at its closest to Earth and moving most quickly along its orbital path, the Moon itself doesnt rotate quite fast enough to keep entirely the same side facing us, and we get to see a little more of the eastern side of the Moon. When the Moon is farthest from Earth and orbiting at its slowest, its rotation gets a little ahead, and we see a bit more of its western side. We call this motion libration in longitude.
The 5 degree tilt of the Moons orbit also causes it to appear to nod, as though it were saying yes. The tilt sometimes brings the Moon above Earths northern hemisphere, and sometimes below Earths southern hemisphere, allowing us to see slightly more of the northern or southern hemispheres of the Moon. We call this motion libration in latitude.
Finally, the Moon appears to tilt back and forth like a metronome. The tilt of the Moons orbit contributes to this, but its mostly due to the tilt of our Earth. Earth has a tilt of 23.5 degrees on its axis, which means that when we observe the Moon from Earth, its a little like were standing sideways on a ramp. If you look left, the ramp slopes up. If you look right, the ramp slopes down. In front of you, the horizon looks higher on the right and lower on the left. If you turn around, the horizon appears to tilt the opposite way.
The tilted ramp works the same as the tilted platform of the Earth beneath our feet. Every two weeks, we have to look in the opposite direction to see the Moon, and the ground beneath our feet is then tilted the opposite way as well.
Sometimes, when the Moon is in one of its crescent phases, we can still see the darkened area of the Moons nearside shining dimly. This effect is caused by the Suns light reflecting off Earths surface onto the face of the Moon. Because Earth at that point in its orbit is nearly full from the Moons perspective, the light it reflects, called earthshine, is bright enough to dimly illuminate the darkened surface.
Though the Moon is often thought of as a nighttime visitor, its also visible during the day as a faint, pale presence. The best times to see a daytime Moon are perhaps during the first and last quarter phases, when the Moon is high enough above the horizon and at about 90 degrees from the Sun in the sky. This helps make the Suns reflected light bright enough to see as it reflects off of the Moon. The Moon can be seen in the daylit sky at any phase except for the new moon, when its invisible to us, and full moon, when its below the horizon during the day. The crescent through quarter phases are high in the sky during the day, but the daytime gibbous phases can be glimpsed only just before the Sun sets.
Spend the next month getting to know the Moon and its phases by filling out your own observation journal.
Have you ever wondered when the next full moon will be? How about the first quarter moon? Put the dates and times for all the Moon's phases for the year at your fingertips by building your own Moon Phases Calendar and Calculator!
Moon phases can be hard to visualize. This simple activity uses a lamp, styrofoam ball and pencil to show how phases work.
More here:
Moon Phases | Moon in Motion Moon: NASA Science
- A Murder At The End Of The World's Retreat Guests Explained: Who ... - Screen Rant - November 18th, 2023 [November 18th, 2023]
- The Moon People: Assimilation and the Jewish Literary Transvestite - Tablet Magazine - November 18th, 2023 [November 18th, 2023]
- Will two generations of Moon walkers shake hands? - OnlySky Media - November 18th, 2023 [November 18th, 2023]
- SpaceX Prepares for Second Starship Launch as it Eyes Moon and ... - OPP.Today - November 18th, 2023 [November 18th, 2023]
- Invincible Season 2 Episode 3 Review - But Why Tho? - November 18th, 2023 [November 18th, 2023]
- TV Recap: "A Murder at the End of the World" - Chapter 1: Homme ... - Laughing Place - November 18th, 2023 [November 18th, 2023]
- Thursday: Hili dialogue Why Evolution Is True - Why Evolution Is True - November 18th, 2023 [November 18th, 2023]
- Space Habitat Market to grow by USD 169.38 million from 2023 to ... - PR Newswire - November 18th, 2023 [November 18th, 2023]
- Cosmic conservation: Why experts argue portions of the solar ... - Salon - September 11th, 2023 [September 11th, 2023]
- We havent even set foot on Mars and we are already setting up a ... - Softonic EN - September 11th, 2023 [September 11th, 2023]
- NASA's MOXIE Experiment Triumphs in Generating Oxygen ... - The Weather Channel - September 11th, 2023 [September 11th, 2023]
- ECOVIEWS: Thermal vents produce bizarre life forms | Features ... - Charleston Post Courier - September 11th, 2023 [September 11th, 2023]
- Elon Musk's 'most powerful rocket ever made' is finally ready for launch - Technext - September 11th, 2023 [September 11th, 2023]
- What's the Bare Minimum Number of People for a Mars Habitat? - Universe Today - September 11th, 2023 [September 11th, 2023]
- India may be moving to change its name to ancient Sanskrit term ... - FOX Bangor/ABC 7 News and Stories - September 11th, 2023 [September 11th, 2023]
- My Nuclear Family - The Good Men Project - September 11th, 2023 [September 11th, 2023]
- The MCU Multiverse Is Continuing A Great Marvel Trend - Screen Rant - April 30th, 2023 [April 30th, 2023]
- How Starship Will Change Humanity Soon - by Tomas Pueyo - Uncharted Territories - April 30th, 2023 [April 30th, 2023]
- China is taking 3D printers to the moon - TechRadar - April 27th, 2023 [April 27th, 2023]
- Mae Martins SAP showcases affirming, optimistic humor - The Wellesley News - April 27th, 2023 [April 27th, 2023]
- Of Moths and Marsupials - bioGraphic - April 27th, 2023 [April 27th, 2023]
- Teachers Rejoice! OpenAI Released Tool to Catch ChatGPT Writing - January 31st, 2023 [January 31st, 2023]
- Are You Smarter Than ChatGPT? OpenAI Tool Aims to Detect AI-Generated ... - January 31st, 2023 [January 31st, 2023]
- What is Artificial Intelligence (AI) ? | IBM - January 31st, 2023 [January 31st, 2023]
- Overview | Earth's Moon NASA Solar System Exploration - January 27th, 2023 [January 27th, 2023]
- All About the Moon | NASA Space Place NASA Science for Kids - January 27th, 2023 [January 27th, 2023]
- January 21, 2023: Closest New Moon Since the Middle Ages - January 27th, 2023 [January 27th, 2023]
- Colonization of Europa - Wikipedia - January 4th, 2023 [January 4th, 2023]
- American Colonization Society | abolitionist organization - January 4th, 2023 [January 4th, 2023]
- Deimos (moon) - Wikipedia - December 28th, 2022 [December 28th, 2022]
- Everything NASA is taking to the moon before colonizing Mars - December 21st, 2022 [December 21st, 2022]
- Chinese Lunar Exploration Program - Wikipedia - December 21st, 2022 [December 21st, 2022]
- Moon - Wikipedia - November 23rd, 2022 [November 23rd, 2022]
- Artemis is our first step toward space colonization - Big Think - November 21st, 2022 [November 21st, 2022]
- Supermoon - Wikipedia - October 15th, 2022 [October 15th, 2022]
- Captain Kirk Went to Space and Saw Absolutely Nothing - TheStranger.com - October 15th, 2022 [October 15th, 2022]
- We'koqma'q First Nation helps keep tradition alive with ribbon skirt bank - CBC.ca - October 15th, 2022 [October 15th, 2022]
- Review: Andor Episode 6 gives a heartbreaking victory to the rebels of Aldhani - Winter is Coming - October 15th, 2022 [October 15th, 2022]
- National Indigenous Peoples Day 2022: Everything to Know - Newsweek - October 15th, 2022 [October 15th, 2022]
- Who's the enemy here? - The Korea JoongAng Daily - October 15th, 2022 [October 15th, 2022]
- Avatar: Where We Were and Where We're at The Minnesota Republic - Kent Kaiser - October 6th, 2022 [October 6th, 2022]
- Glitching Time and Time-Based Media The Brooklyn Rail - Brooklyn Rail - October 6th, 2022 [October 6th, 2022]
- New Artwork on the Toronto Sign Pays Tribute to the Rights of Indigenous Language Speakers Worldwide - Storeys - September 29th, 2022 [September 29th, 2022]
- Is it finally time for a permanent base on the moon? - Popular Science - September 22nd, 2022 [September 22nd, 2022]
- Venice Review: In Viaggio is a Fascinating Rorschach Test of the Pope - The Film Stage - September 22nd, 2022 [September 22nd, 2022]
- Bon Apptit's 2022 Heads of the Table Awards - Bon Appetit - September 22nd, 2022 [September 22nd, 2022]
- Coast Salish sweat-lodge keeper welcomes all to share in healing - Broadview Magazine - September 22nd, 2022 [September 22nd, 2022]
- In Guam, even the dead are dying: the US military is building on the graves of our ancestors - The Guardian - September 22nd, 2022 [September 22nd, 2022]
- Living Underground on the Moon: How Lava Tubes Could Aid Lunar Colonization - August 25th, 2022 [August 25th, 2022]
- Colonization of the Solar System - Wikipedia - August 25th, 2022 [August 25th, 2022]
- Under Capitalism, the Colonization of Space Means the ... - Jacobin - August 25th, 2022 [August 25th, 2022]
- A New World of Heavenly Art - The Epoch Times - August 25th, 2022 [August 25th, 2022]
- New Releases Tuesday: The Best Books Out This Week - Book Riot - August 25th, 2022 [August 25th, 2022]
- Diving into student research at the Summer 2022 SEA Fellows Symposium - UMaine News - University of Maine - University of Maine - August 25th, 2022 [August 25th, 2022]
- Skywatch for the week of August 22, 2022 - WQCS - August 23rd, 2022 [August 23rd, 2022]
- Law alum's career heads into orbit with unexpected passion for space law - University of Calgary - August 23rd, 2022 [August 23rd, 2022]
- Heres where we might really be able to set up a colony on the Moon - BGR - August 10th, 2022 [August 10th, 2022]
- Elon Musk's Flawed Vision and the Dangers of Trusting Billionaires - TIME - August 10th, 2022 [August 10th, 2022]
- Travel Bug: You don't have to be a diver to enjoy Palau - Pacific Daily News - August 10th, 2022 [August 10th, 2022]
- Avatar Was James Cameron's Tribute To A Legend Of VFX Filmmaking - /Film - July 31st, 2022 [July 31st, 2022]
- Sonic Youth : Sister, EVOL, Bad Moon Rising - The trilogy | Treble - Treble - July 31st, 2022 [July 31st, 2022]
- NASA's Lunar Orbiter spots comfortably warm 'pits' all over the Moon - The Register - July 27th, 2022 [July 27th, 2022]
- Will 3D Printing Be Used for the First Commercial Mission to Mars? - 3Dnatives - July 27th, 2022 [July 27th, 2022]
- Abe Leaves Behind Complex Legacy in Japan's Neighborhood - The Diplomat - July 27th, 2022 [July 27th, 2022]
- Moon Off-Roading In The Wild GM Electric Car That Makes Hummer EV Look Normal - SlashGear - June 30th, 2022 [June 30th, 2022]
- A conversation with a poet whose home burned to the ground - Yale Climate Connections - June 30th, 2022 [June 30th, 2022]
- Before Langley Air Force Base: The muddy history of Shellbanks, Sherwood and other plantations of Elizabeth City County - Daily Press - June 30th, 2022 [June 30th, 2022]
- colonization of Australia | Britannica - June 24th, 2022 [June 24th, 2022]
- NASA Reveals Three Design Concepts For Nuclear Power On The Moon - SlashGear - June 24th, 2022 [June 24th, 2022]
- Interview: Small modular reactors get a reality check about their waste - Bulletin of the Atomic Scientists - June 22nd, 2022 [June 22nd, 2022]
- Of Wazhazhe Land and Language: The Ongoing Project of Ancestral Work - Literary Hub - June 22nd, 2022 [June 22nd, 2022]
- The Oddest of Organs: A Brief History of the Tongue - Literary Hub - June 22nd, 2022 [June 22nd, 2022]
- 'For All Mankind' Season 3: Episode 2 - Recap And Ending, Explained - Who Was Chosen To Head The Mars Mission? | DMT - DMT - June 20th, 2022 [June 20th, 2022]
- New moon - Wikipedia - June 11th, 2022 [June 11th, 2022]
- Why Neil deGrasse Tyson Is Skeptical About Mars Colonization - June 3rd, 2022 [June 3rd, 2022]
- Bitcoin And The Great Filter - Bitcoin Magazine - June 3rd, 2022 [June 3rd, 2022]
- Art Attack: Where to Find Art on First Friday Weekend in Denver - Westword - June 3rd, 2022 [June 3rd, 2022]
- Scramble Campbell on His Two Decades as Red Rocks' Artist-in-Residence - Westword - June 3rd, 2022 [June 3rd, 2022]
- Pro and Con: Space Colonization | Britannica - May 31st, 2022 [May 31st, 2022]
- How Many Humans Could the Moon Support? | Live Science - May 31st, 2022 [May 31st, 2022]