Daily Archives: January 27, 2023

Earth's Moon is the only place beyond Earth where humans have set foot.

The brightest and largest object in our night sky, the Moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate. It also causes tides, creating a rhythm that has guided humans for thousands of years. The Moon was likely formed after a Mars-sized body collided with Earth.

Earth's Moon is the fifth largest of the 200+ moons orbiting planets in our solar system.

Earth's only natural satellite is simply called "the Moon" because people didn't know other moons existed until Galileo Galilei discovered four moons orbiting Jupiter in 1610.

NASA currently has three robotic spacecraft exploring the Moon Lunar Reconnaissance Orbiter and the twin ARTEMIS spacecraft (not to be confused with NASA's new Artemis program to send astronauts back to the Moon).

Explore Earth's Moon In Depth

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If you set a single green pea next to a U.S. nickel, you'd have a pretty good idea of the size of the Moon compared to Earth.

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The Moon is Earth's only natural satellite. It goes around the Earth at a distance of about 239,000 miles (385,000 kilometers).

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The Earth and Moon are tidally locked. Their rotations are so in syncwe only see one side of the Moon. Humans didn't see the lunar far side until a Soviet spacecraft flew past in 1959.

Viewing Copernicus

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The Moon has a solid, rocky surfacecratered and pitted from impacts by asteroids, meteorites, and comets.

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The Moon has a very thin and tenuous atmosphere called an exosphere. It is not breathable.

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More than 105robotic spacecraft have been launched to explore the Moon. It is the only celestial body beyond Earth so far visited by human beings.

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The Moon's weak atmosphere and its lack of liquid water cannot support life as we know it.

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Apollo astronauts brought back a total of 842 pounds (382 kilograms) of lunar rocks and soil to Earth. We are still studying them.

Apollo 11 Bootprint

The Moon was the first place beyond Earth humans tried to reach as the Space Age began in the late 1950s. More than 100 robotic explorers from more than half a dozen nations have since sent spacecraft to the Moon. Nine crewed missions have flown to the Moon and back.

The former Soviet Union logged the first successes with its Luna program, starting with Luna 1 in 1959. NASA followed with a series of robotic Ranger and Surveyor spacecraft that performed increasingly complex tasks that made it possible for the first human beings to walk on the Moon in 1969.

Twenty-four humans have traveled from the Earth to the Moon. Twelve walked on its surface. The last human visited the lunar surface in 1972.

"That's one small step for a man. One giant leap for mankind."

Now NASA is gearing up to set up a permanent lunar presence on the Moon. The Artemis program will send the first woman and the next man to the Moon and develop a sustainable human presence on the Moon and set the stage for further human exploration of Mars.

The program takes its name from the twin sister of Apollo and the goddess of the Moon in Greek mythology. Artemis 1, formerly Exploration Mission-1, is the first in a series of increasingly complex missions that will enable human exploration of the Moon and Mars.

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During a lunar eclipse, Earth comes between the Sun and the Moon, blocking the sunlight from falling on the Moon. There are two kinds of lunar eclipses:

During some stages of a lunar eclipse, the Moon can appear reddish. This is because the only remaining sunlight reaching the Moon at that point is from around the edges of the Earth, as seen from the Moon's surface. From there, an observer during an eclipse would see all of Earth's sunrises and sunsets at once.

Our lunar neighbor has inspired stories since the first humans looked up at the sky and saw its gray, cratered surface. Some observers saw among the craters the shape of a person's face, so stories refer to a mysterious "man in the Moon." Hungrier observers compared the craters to cheese and dreamed of an entire sphere made of delicious dairy products.

The Moon made its film debut in a 1902 black and white silent French film called "Le Voyage Dans la Lune" ("A Trip to the Moon"). And a year before astronauts walked on the Moon, "2001: A Space Odyssey" (1968) told the story of astronauts on an outpost on the Moon. Decades later, it is still widely regarded as one of the best science fiction movies ever made.

American astronauts have planted six American flags on the Moon. But that doesn't mean the United States has claimed it; in fact, an international law written in 1967 prevents any single nation from owning planets, stars, or any other natural objects in space.

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Overview | Earth's Moon NASA Solar System Exploration

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

Quick Facts:

Earth has just one moon a rocky, cratered place, roughly a quarter the size of Earth and an average of 238,855 miles away. The Moon can be seen with the naked eye most nights as it traces its 27-day orbit around our planet.

Explore the Moon! Click and drag to rotate the Moon. Scroll or pinch to zoom in and out. Credit: NASA Visualization Technology Applications and Development (VTAD)

This is the face of the Moon that we see from Earth. This image is based on data from NASAs Lunar Reconnaissance Orbiter spacecraft. Credit: NASA/GSFC/Arizona State University

Chances are that when you imagine the night sky, one of the first things that comes to mind is the Moon glowing in the darkness. The Moon has always held a special place in our imaginations and in daily life.

The Moon has inspired wonder and creativity for thousands of years. This image appeared in a 1902 French film called "Le Voyage dans la Lune" ("A Trip to the Moon").

Its no wonder that we are fascinated. The Moon is Earths only natural satellite and one that we can easily see most nights.

The Moon does not shine with its own light. It simply reflects light coming from the Sun.

From Earth, it might look like the Moon is changing shape each night from a tiny sliver to a half moon to a full moon and back again. Whats actually happening is that from our spot on Earth, we see different parts of the Moon lit up by the Sun as the Moon travels in its orbit.

As the Moon travels around Earth, different parts of it are lit up by the Sun. These changes in the Moon's appearance from our view on Earth are called moon phases. This graphic shows all eight moon phases we see as the Moon makes a complete orbit of Earth about every four weeks. Credit: NASA/JPL-Caltech

No. The Moon rotates on its own axis at the same rate that it orbits around Earth. That means we always see the same side of the Moon from our position on Earth. The side we don't see gets just as much light, so a more accurate name for that part of the Moon is the "far side."

We only ever see one side of the Moon because as it orbits around Earth, it also rotates on its own axis at the same speed. Credit: NASA/JPL-Caltech

The "far side" of the Moon looks very different than the near side (see the first photo in this article). Notice how few dark areas the far side has. This image is based on data from NASAs Lunar Reconnaissance Orbiter spacecraft. Credit: NASA/Goddard Space Flight Center/Arizona State University

Scientists believe that the Moon formed early in the solar systems history after Earth and an object about the size of Mars smashed into each other. The impact sent chunks of Earth and the impactor into space that were pulled together by gravity, creating the Moon.

Even thousands of years ago, humans drew pictures to track the changes of the Moon. Later, people used their observations of the Moon to create calendars.

Today, we study the Moon using telescopes and spacecraft. For example, NASA's Lunar Reconnaissance Orbiter has been circling the Moon and sending back measurements since 2009.

The Moon is the only other planetary body that humans have visited. On July 20, 1969, NASA astronauts Neil Armstrong and Buzz Aldrin were the first people to set foot on the dusty surface of the Moon. Ten other American astronauts followed. They collected hundreds of pounds of lunar soil and rock samples, conducted experiments and installed equipment for follow-up measurements.

Astronaut Buzz Aldrin set up several scientific experiments while on the surface of the Moon during the historic Apollo 11 mission. You can see the lunar module, Eagle, in the background. Credit: NASA

Today, we know that the Moon is covered by craters as well as dust and debris from comets, asteroids and meteoroid impacts. We know that the Moons dark areas, called maria which is Latin for seas are not actually seas. Instead, they are craters that lava seeped into billions of years ago. We know that the Moon has almost no atmosphere and only about one-sixth of Earths gravity. We even know that there is quite a bit of frozen water tucked away in craters near the Moon's poles.

There is no wind or air on the Moon to help erase craters, so the surface is covered with the remains of old and new impacts. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

There are still many questions left to answer about the Moon. And the most exciting days of lunar activity may still lie ahead as NASA sends humans on the next missions to the Moon and eventually on to Mars!

NASA Solar System Exploration

See more here:
All About the Moon | NASA Space Place NASA Science for Kids

This Saturdays New Moon will be the closest New Moon to Earth in a period of 1337 years.

The New Moon of January 2023 coincides with the point in the Moons orbit where it is closest to Earth.

timeanddate

According to our calculations, on January 21, 2023, the New Moon will be at its closest distance to Earth for the last 992 years.

The next time the New Moon is this close to Earth will be 345 years from now, making this the closest New Moon in 1337 years.

Moon phases visualizedwhere is the Moon?

The Moons orbit around Earth is not a perfect circle. Instead, it has an elliptical shape, like a slightly stretched circle. This means the distance between the Moon and Earth changes over the course of a month.

The point on the Moons orbit that is closest to Earth is called perigee; the farthest point is called apogee.

If perigee or apogee coincides with a New Moon or Full Moonwhen the Earth, Moon, and Sun are in alignmentthe Moons closest and farthest distances become more extreme.

This leads to the phenomena of Supermoons and Micromoons, where the Moon is particularly near or far away.

The most extreme Earth-Moon distances of all occur when Earth is near its closest point to the Sun, which is called perihelion. Currently, perihelion falls around the beginning of January.

We looked into the closest Earth-Moon distances at New Moon over a 2000-year period, and found three New Moons where the distance was less than 356,570 km (221,562 miles).

Our calculations used the best available figures for the Moons position over long periods of time. This is a set of data called DE431, which was produced by the Jet Propulsion Laboratory at the California Institute of Technology.

Sources: JPL Ephemeris DE431, timeanddate.com

It should be noted that, according to this data, there is only a few kilometers difference between these distances. It can also be seen that the three dates fall close to perihelion (around December and January).

As a comparison, the farthest Earth-Moon distance is typically around 405,000 km (252,000 miles).

So this will be the closest New Moonand also, therefore, the largestsince the 11th century.

In practical terms, we wont be able to see anything, because the New Moon is known as the invisible phase: its where the Moon disappears from view for a few days.

Supermoons and Micromoons do have a small effect on tides. And, of course, anything to do with the Moon has the potential to fill us with wonder and curiosity.

In fact, this will be a weekend of astronomical close encounters.

On Sunday, January 22, Venus will appear to pass within 0.34 of Saturn. This is less than the width of a little finger held at arms length.

Venus and Saturn appear as a single star in this view from our Night Sky Map for New York City at 17:30 (5:30 pm) local time on January 22. Saturn will be much fainter than bright Venus. This image also includes the super-thin crescent of a one-day-old Moon.

timeanddate

Find Venus and Saturn on our Night Sky Map

In a session at last years Europlanet Science Congress in Granada, Spain, timeanddate highlighted this event as one of seven notable close approaches of planets between now and 2040.

See original here:
January 21, 2023: Closest New Moon Since the Middle Ages