Posted on by Tammy Plotner

The Weekend SkyWatcher’s Forecast: May 9-11, 2008

Atlas Map

Greetings, fellow SkyWatchers! Are you ready for a very incredible weekend? The action begins on Friday as we take you on a guided tour of the lunar surface. On Saturday, celebrate Astronomy Day with a very special unaided eye sky event and a return to the Moon. No rest for the wicked on Sunday… Because you’ll be seeing double! Time to get out your binoculars and telescopes and turn an eye to the sky, because…. Here’s what’s up!

Friday, May 9 – Today in 1962, the first Earth-based laser was aimed at crater Albategnius. Although it isn’t visible tonight, let’s take a look at what is visible just 1.5 light-seconds away! First is a Lunar Club challenge which won’t prove difficult because you’ll be working with a map. Relax! This will be much easier than you think. Starting at Mare Crisium, move along the terminator to the north following the chain of craters until you identify a featureless oval which looks similar to Plato seen on a curve. This is Endymion…and if you can’t spot it, don’t worry. Let’s take a look at some features which will point you to it!

Most prominent of all will be two craters to the north named Atlas and Hercules. The easternmost Atlas was named for the mythical figure who bore the weight of the world on his shoulders, and the crater spans 87 kilometers and contains a vivid Y-shaped rima in the interior basin. Western Hercules is considerably smaller at 69 kilometers in diameter, and shows a deep interior crater called G. Power up and look for the tiny E crater which marks the southern crater rim. North of both is another unusual feature which many observers miss. It is a much more eroded and far older crater which only shows a basic outline and is only known as Atlas E.

Since we’re here, let’s take a crater walk and see how many features we can identify… Good luck, and clear skies!

Atlas Map

(1) Mare Humboldtianum, (2) Endymion, (3) Atlas, (4) Hercules, (5) Chevalier, (6) Shuckburgh, (7) Hooke, (8) Cepheus, (9) Franklin, (10) Berzelius, (11) Maury, (12) Lacus Somniorum, (13) Daniel, (14) Grove, (15) Williams, (16) Mason, (17) Plana, (18) Burg, (19) Lacus Mortis, (20) Baily, (21) Atlas E, (22) Keldysh, (23) Mare Frigoris, (24) Democritus, (25) Gartner, (26) Schwabe, (27) Thales, (28) Strabo, (29) de la Rue, (30) Hayn.

Saturday, May 10 – Today is Astronomy Day and something wonderful is happening in the sky! Somewhere out there, the Moon is silently occulting Mars, and the Red Planet will be hauntingly close to the limb as the skies darken… For observers through India and Europe, you have the chance to watch the occultation, so visit IOTA for specific times in your location!

Fabricius

Tonight let’s journey to the Moon as we look at a beautiful series of craters – Fabricius, Metius and Rheita. Bordered on the south by shallow Jannsen, Lunar Club challenge Fabricius is a 78 kilometer diameter crater highlighted by two small interior mountain ranges. To its northeast is Metius, which is slightly larger with a diameter of 88 kilometers. Look carefully at the two. Metius has much steeper walls, while Fabricius shows differing levels and heights. Metius’ smooth floor also contains a very prominent B crater on the inside of its southeast crater wall. Further northeast is the lovely Rheita Valley which stretches almost 500 kilometers and appears more like a series of confluent craters than a fault line. 70 kilometer diameter crater Rheita is far younger than this formation because it intrudes upon it. Look for a bright point inside the crater which is its central peak.

Since tonight will be our last chance to galaxy hunt for a while when the Moon has westered, let’s take a look at one of the brightest members of the Virgo Cluster – M49. Located about eight degrees northwest of Delta Virginis almost directly between a pair of 6th magnitude stars (RA 12 29 46 Dec +07 59 59), the giant elliptical M49 holds the distinction of being the first galaxy in the Virgo cluster to be discovered – and only the second beyond our local group. At magnitude 8.5, this type E4 galaxy will appear as an evenly illuminated egg shape in almost all scopes, and as a faint patch in binoculars. While a possible supernova event occurred in 1969, don’t confuse the foreground star noted by Herschel with something new!

Although most telescopes won’t be able to pick this region apart – especially with the Moon so near – there are also many fainter companions near M49, including NGC 4470. But a sharp-eyed observer named Halton Arp noticed them and listed them as Peculiar Galaxy 134 – one with “fragments!”

Sunday, May 11 – Tonight no two lunar features in the north will be more prominent than Aristoteles and Eudoxus. Viewable even in small binoculars, let’s take a closer look at larger Aristoteles to the north.

Aristoteles

As a Class I crater, this ancient old beauty has some of the most massive walls of any lunar feature. Named for the great philosopher, it stretches across 87 kilometers of lunar landscape and drops below the average surface level to a depth of 366 meters – a distance which is similar to Earth’s tallest waterfall, the Silver Cord Cascade. While it has a few scattered interior peaks, the crater floor remains almost unscarred. As a telescopic Lunar Club challenge, be sure to look for a much older crater sitting on Aristoteles’ eastern edge. Tiny Mitchell is extremely shallow by comparison and only spans 30 kilometers. Look carefully at this formation, for although Aristoteles overlaps Mitchell, the smaller crater is actually part of the vast system of ridges which supports the larger one.

PorrimaWhen you’re done, let’s have a look at another delightful pair that’s joined together – Gamma Virginis…

Better known as Porrima, this is one cool binary; whose members are nearly equal in spectral type and brightness. Discovered by Bradley and Pound in 1718, John Herschel was the first to predict this pair’s orbit in 1833 and state that one day they would become inseparable to all but the very largest of telescopes – and he was right. In 1920 the A and B stars had reached their maximum separation, but during 2007 they were as close together as they will ever be in our lifetimes. Observed as a single star in 1836 by William Herschel, its 171 year periastron now puts Porrima almost the same position as it was when Sir William saw it!

Have a great weekend… 😉

This week’s awesome images: Atlas Crater Map Image: Greg Konkel Annotations: Tammy Plotner – Fabricius, Metius and Rheita – Credit: Alan Chu – Aristoteles – Credit: Wes Higgins – Gamma Virginis: Porrima – Credit: Palomar Observatory, courtesy of Caltech. Thank you!!

Posted on by Nancy Atkinson

Popular Space Elevator Video Not “News,” says LiftPort Founder

An online video that’s been circulating like wildfire on the internet recently is actually almost two years old, says Michael Laine, founder of LiftPort, a company looking to develop a space elevator. The video was taken in the fall of 2006, at least 20 months ago.

The video has been downloaded over 200,000 times in the past few days, and has been extremely popular on sites like Digg. “I find the whole thing kind of a farce, actually,” said Laine. “I’m glad people are seeing it and commenting on it, but if someone thinks this is news, its not.”

The only reason Laine could site for a possible resurgence of this video is that last Friday, the Conan O’Brien show featured a guest talking about space elevators. Laine wonders if that led to people doing searches about the subject, finding this old video on You Tube, and re-posting it as “new.” Laine says LiftPort has received slightly more email than normal the past couple of days, but until now no one has contacted him to check on the authenticity or timing of the video.

“Everything in it is true, except the timing is strange,” said Laine. “Those are my quotes, (listed along with the video) but I don’t know how someone obtained them, and got that wording. What’s ironic is that we’ve done a lot of experiments since then. That specific test was supposed to be a mile high test, but we had problems with the ribbon snapping. The FAA required that we put markers on it, and the acetone used to mark it weakened the ribbon substantially. The test turned out to be 1,000 feet. We actually were very happy about the test, although we almost lost the ribbon.”

Laine was especially surprise to hear of this new interest in Liftport, since the company has gone through some hard times over the past year, losing investors, a building, and other support. Laine said he will have some positive news to report soon, so stay tuned.

And OK, here’s the video. (You Tube’s version, not LiveLeak’s!) It is pretty amazing.

Click here for more information about LiftPort.

Posted on by Fraser Cain

How Far is Mercury from Earth?

Orbit of Mercury

Although Galileo wasn’t able to see the phases of Mercury (like the phases of Venus and the Moon) with his first crude telescope, the astronomers that carried on his discoveries did. This was powerful evidence that both Mercury and Earth are orbiting the Sun.

You can also check out these amazing books for more information about the planet Mercury.

Since Mercury orbits the Sun, and it follows a very elliptical path on its journey around the Sun, our two planets can vary their distance significantly.

When Mercury is at its closest point to Earth, astronomers call this opposition (from the point of view of Mercury). This would happen when Mercury was at its furthest from the Sun, and Earth is at its closest. When this happens, Mercury and Earth would be separated by only 77 million km (48 million miles).

Their maximum distance occur when Earth is at its furthest point from the Sun, and Mercury is at its maximum on the other side of the Sun. The three objects then line up perfectly. At this point, Mercury and Earth can be 222 million km (138 million miles) apart.

Distancia desde la Tierra a Mercurio

Posted on by Jerry Coffey

How Far is Venus from Earth?

The are varying numbers for the Venus distance from Earth. Each number depends on the relative position of each planet in its elliptical orbit. The point when the planets are at their closest approach to each other is called opposition. The distance between the planets can even vary at different oppositions. The closest possible opposition distance between Earth and Venus is 38 million kilometers. This is the closest that any planet comes to Earth.

The farthest that Venus ever gets from Earth is 261 million km. The means that the Venus distance from Earth can vary by an incredible 223 million km. While that seems like an amazing distance, it is nothing compared to the numbers attributed to other planets. Try to imagine how far it is between Earth and Neptune. Here is a link that tells you how to figure those distances out.

The relative proximity of Venus helps to explain why it is the second brightest object in the night sky. The planet has an apparent magnitude of about -4.9 at its brightest. It can also completely disappear from the night sky when it is at its most distant, because the Sun is between it and the Earth. The planet’s apparent magnitude is also helped by the reflectivity of the sulfuric acid clouds that dominate its atmosphere. The clouds reflect a great deal of visible light, increasing the planet’s albedo and making it more readily seen.

Venus will periodically pass across the face of the sun. This is called a transit. These transits of Venus occur in pairs with more than a century separating each pair. Since the advent of the telescope, transits have been observed in 1631, 1639; 1761, 1769; and 1874, 1882. the most recent occurred on June 8, 2004. The second in this pair will occur on June 6, 2012, so mark your calenders and prepare your telescopes. The planet can also be seen to go through phases much like the Moon when you observe it through powerful binoculars or small telescopes.

Venus is always brighter than any star. It is at its brightest when the Venus distance from Earth is the smallest. The planet can be easy to see when the Sun is low on the horizon, it always lies about 47° from the Sun. The planet orbits faster than the Earth, so overtakes it every 584 days. When this happens Venus is more easily seen in the morning, just after sunrise. Hopefully, you have found quite a bit of useful information here.

We have written many articles about Venus for Universe Today. Here are some interesting facts about Venus, and here’s an article about Venus compared to Earth.

If you’d like more information on Venus, check out Hubblesite’s News Releases about Venus, and here’s a link to NASA’s Solar System Exploration Guide on Venus.

We’ve also recorded an entire episode of Astronomy Cast all about Venus. Listen here, Episode 50: Venus.

References:
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Venus&Display=OverviewLong
http://curious.astro.cornell.edu/question.php?number=564

Posted on by Tammy Plotner

Astronomy Day – May 10, 2008

Are you ready for Astronomy Day? Astronomy Day is a grass roots movement designed to share the joy of astronomy with the general population – “Bringing Astronomy to the People.” During this year’s Astronomy Day on May 10, thousands of people who have never looked through a telescope will have an opportunity to see first hand what has so many amateur and professional astronomers all excited!

Astronomy clubs, science museums, observatories, universities, planetariums, laboratories, libraries, and nature centers host special events and activities to acquaint their population with local astronomical resources and facilities. Many of these events are located at non-astronomical sites; shopping malls, parks, urban centers – truly Bringing Astronomy to the People. If you’re interested in attending such an event, take a look at where current Astronomy Day events being held. This list only encompasses those groups who choose to advertise on the Astronomical League website, so please be sure to check your local news media for other events.

If you, your facility, group or astronomy club is interested in planning astronomy day activities, perhaps you’d like some help! By following the link to the Sky and Telescope Astronomy Day Handbook you can get some great pointers and ideas by downloading the free handbook written by David Levy. While on the page, be sure to visit other great links such as Let’s Go Stargazing and downloadable handouts like the Good Neighbor Outdoor Lighting flyer. The Astronomical League also offers Graphics For Astronomy Day Events and you can even enter your activities in the annual Sky and Telescope Astronomy Award Program!

Need more fun things to do for Astronomy Day that you can reach with just a mouse click? Then know the Abrams Sky Calendar is available for Astronomy Day activities. Anyone celebrating the event is welcome to distribute any number of copies of the Sky Calendar or Sample Sky Map with no restrictions, other than we ask that material not be deleted. How about kid’s activities? Let’s start with coloring pages for Jupiter, Saturn and Mars. You can even make your own Solar System Mobile!

Astronomy Day is an astronomical public relations event that helps highlight ways the general public can get involved with astronomy – or at least get some of their questions about astronomy answered. This important event – Astronomy Day – is co-sponsored by 14 astronomical and astronomy education organizations. They are: The Astronomical League, The Astronomical Society of the Pacific, the Royal Astronomical Society of Canada, the American Astronomical Society, the Astronomical Association of Northern California, the Western Amateur Astronomers, the American Association of Physics Teachers, the Association of Lunar and Planetary Observers, the American Meteor Society, the American Association of Variable Star Observers, the Planetary Society, the National Space Society, the International Planetarium Society, the Association of Astronomy Educators, and the International Astronomical Union.

As the Executive Secretary of the Astronomical League, I’m here to answer any Astronomy Day questions you might have – or point you in the right direction. Spend a few minutes coloring with a child, set up your telescope for a neighbor, take binoculars to work, make copies of the Sky Calendar and Maps and post in your local library. No matter what the size or your event, or level of involvement, it’s all about sharing what you love to do with others. Celebrate Astronomy Day!

Posted on by Jerry Coffey

Atmosphere of Venus



Earth and Venus share many physical characteristics. Atmosphere is not one of them. The atmosphere of Venus is so harsh that it is the main reason that no one has ever been able to make optical observations of anything other than the planet’s upper atmosphere.

Visualization of the planet is made impossible be the high amounts of sulfuric acid in the atmosphere. Clouds in the upper atmosphere are full of sulfuric acid droplets. Sulfur is highly reflective of visible light, thus preventing observation much deeper than the upper limits of the clouds themselves.

The next challenge that the atmosphere of Venus presents is its composition. It is made up of 96% carbon dioxide. Oxygen can not be detected even as a trace element. At the surface the atmospheric pressure is 92 times that of Earth. If you were able to find a way to survive the intense pressure and had enough oxygen, you would be standing on a surface that is hot enough to melt lead. The temperature across Venus, from pole to pole, is a steady 462°C as a result of the atmosphere’s greenhouse qualities. In the hottest parts of the hottest deserts here on Earth, the temperatures never top 50°C.

The sweltering surface of the planet is covered by volcanoes, impact craters, and old lava flows. There are 1,000 volcanic craters and crater remnants that are over 20 km in diameter. The surface has never been impacted by a small meteorite. The atmosphere burns up anything small. It could take an asteroid in excess of 50 km to survive long enough to hit the surface and then it would have lost close to half of its mass in the atmosphere. The entire planet was resurfaced by volcanic flows between 300 and 500 million years ago.

Several spacecraft have entered the atmosphere of Venus. The first successful probe was the Soviet mission Venera 3, but its instruments failed before entry. Venera 4successfully deployed a number of science experiments. They showed a surface temperature of almost 500°C and an atmosphere that was 90 to 95% carbon dioxide. The atmosphere was much denser than anticipated and its slower descent caused its batteries to run down before reaching the surface. NASA’s Mariner 5 reached the planet one day after Venera 4, but only flew by. The data from the two missions were compared and were an early step in international space exploration cooperation. The Soviet space agency also launched Venera’s 5 and 6. They returned a great deal of information, but were crushed by atmospheric pressure within 20 km of the surface.

There have been over a dozen missions to study the surface and atmosphere of Venus since the Venera program. Currently, the Venus Express mission is in orbit. Bepicolumbo and the Venus in-Situ Explorer are planned. Each mission returns new data, it is hard to imagine what mysteries may be unraveled with a surface explorer.

We have written many articles about Venus for Universe Today. Here are some interesting facts about Venus, and here are some pictures of planet Venus.

If you’d like more information on Venus, check out Hubblesite’s News Releases about Venus, and here’s a link to NASA’s Solar System Exploration Guide on Venus.

We’ve also recorded an entire episode of Astronomy Cast all about Venus. Listen here, Episode 50: Venus.

References:
http://www.nasa.gov/audience/forstudents/5-8/features/F_The_Planet_Venus_5-8.html
http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Venus&Display=OverviewLong

Posted on by Fraser Cain

History of Planet Venus



Venus is one of the 5 planets visible to the unaided eye, and so it has been seen in the sky since prehistoric times. After the Sun and the Moon, Venus is the brightest object in the sky – brighter than any stars.

Venus is the Roman name for the Greek goddess of love; Aphrodite. But there are references to Venus as far back as Babylonian cuneiformic texts, like the Venus table of Ammisaduqa which could be as old as 1600 BC. Ancient Egyptians thought that Venus was actually two separate objects… a morning star, and then a completely different evening star. The tradition carried on with the ancient Greeks, as well.

The early mathematician Pythagoras was one of the first to recognize that the morning and evening stars were actually the same object: Venus. So perhaps he was the first to “discover Venus”.

The Maya civilization held Venus in high regard, and the planet figured prominently in their religious calendar.

Once he built his first rudimentary telescope, Galileo turned it towards Venus, was was astonished to find that the planet goes through phases like the Moon, going from crescent to gibbous to full and then back again. This was one of the strongest pieces of evidence that Venus goes around the Sun, and not the Earth as others originally believed.

Because Venus has always been obscured by thick clouds, science fiction writers have been free to imagine whatever they wanted existed on the surface of Venus. The clouds helped them to imagine a warm tropical world with constant rainfall and lush vegetation. The truth, of course, is that Venus is a hellish hot world, devoid of life.

Posted on by Tammy Plotner

Spock’s Astronomy Quiz

Leonard Nimoy as Mr. Spock. Credit: CBS Television

Have you ever wanted to test your astronomy knowledge against the best? Then take the warp speed jump to Spock’s Astro Quiz. It’s more than just astronomy trivia, it’s a great way to test your astronomy knowledge, learn more about astronomy related topics and interact via live chat with others interested in astronomy…

Welcome to Spock’s Astro Quiz, a great place to see just how much you know about astronomy and to enjoy the company of astronomy minded individuals. No special knowledge, secret passwords, or fancy hoops to jump through to enjoy the fun… All you have to do is click Log In and get started!

While you’re there, this interactive site will not only allow to test your astronomy skill against Spock’s, but to chat live with astronomy-minded visitors and play against each other as well. Just a word of caution though… Spock plays a clean astronomy game. Use a swear word and you’ll be warned once. Do it again and you’re permanently beamed out. The astronomy quiz and astronomy chat board is continually monitored and safe for players of all ages. Solicitors of any type will be immediately banned.

Test your astronomy skill… Enjoy the company of other astronomy friends during cloudy nights… And live long and prosper!

Brought to you by Macedon Ranges Observatory.

Posted on by Fraser Cain

Pictures of Planet Venus

Venus is one of the brightest objects in the night sky, so it’s not surprising that it’s been photographed many times. Some pictures of Venus have been taken from here on Earth, while other Venus pics have been taken from spacecraft orbiting the planet. You might be surprised to know that spacecraft have even landed on Venus (they didn’t last long), and took images of Venus from the surface.

Surface Image of Venus
This is a picture of Venus captured by NASA’s Magellan spacecraft. It shows the entire surface of the planet, imaged by the spacecraft’s radar instrument, which can penetrate the thick clouds to reveal the surface below. Magellan was launched from the cargo bay of the space shuttle Atlantis in May 1989, and arrived at Venus on August 10, 1990. It orbited the planet for 4 years before plunging to the surface.


3-D Image of Venus’ Surface
This is another photograph of Venus taken by NASA’s Magellan spacecraft. Planetary scientists used the radar data captured by Magellan to build up 3-dimensional images of the planet’s surface. This is an image of the Eistla Regio region, which contains volcanos and impact craters.



Photo of Venus from Pioneer Venus Spacecraft
This was one of the first ever close-up photographs of Venus, captured by NASA’s Pioneer Venus spacecraft. It’s actually a false color image made from ultraviolet images of the planet Venus by the spacecraft. The Pioneer Venus Orbiter went into orbit around Venus on December 4, 1978, and released several probes into Venus’ atmosphere to study it.


The Surface of Venus by Venera
You might be amazed to know that spacecraft have actually landed on the surface of Venus and sent pictures back. The Soviets sent a fleet of Venera spacecraft to Venus, and several actually made it down to the surface. Here’s a color photograph of Venus captured by the Venera 13 spacecraft, which landed on the surface of Venus on March 3, 1982.



Picture of Venus by Venus Express
This is a false-color image of Venus taken by the Venus Monitoring Camera on board ESA’s Venus Express spacecraft. It’s showing the planet’s southern hemisphere, including its south pole. The spacecraft captured the image when it was 35,000 km from the surface of Venus.

Posted on by Fraser Cain

Photos of the Earth and Moon – From Other Worlds

Image taken by the HiRISE camera on NASA's Mars Reconnaissance Orbiter, showing Earth and the Moon. Credit: NASA/JPL

We’re familiar with the close-up images of Earth captured by orbital satellites and astronauts on the International Space Station. But here are a few pictures of the Earth and Moon captured at a distance, while passing around the Moon, or orbiting distant Saturn. In the words of Carl Sagan, “Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.”

Since Sagan commented on Voyager 1’s image of Earth, several more pics of the Earth and Moon have been captured that really put our tiny spot in the Universe into perspective.


Voyager 1 – the Pale Blue Dot
This image, captured by NASA’s Voyager 1 spacecraft on February 14, 1990, is the one Sagan was talking about. It was taken when Voyager 1 was about 6.4 billion kilometres (4 billion miles) from Earth. In this image, the entirety of the planet takes up less than a single pixel; in fact, NASA calculated that we’re only 0.12 pixel in size. Sagan pushed the agency to capture images of all the planets in the Solar System, to create a family portrait seen from Voyager’s distant position.



Cassini – the Earth from Saturn
This is easily the best picture ever captured by NASA’s Cassini spacecraft, and in the running for the best space pictures of all time. It shows Saturn in all its glory, backlit by the Sun. From this view, the rings glow with an ethereal light.

But this image is extra special. Take a look towards the upper left of the image, and you’ll notice a tiny blue-white dot. Once again, there’s Earth, seen from a distance of 1.4 billion km (1 billion miles).


Mars Express – the Earth and Moon from Mars
ESA’s Mars Express captured this image of Earth and the Moon on July 3, 2005 when it was 8 million km (5 million miles). This was actually the first observational data sent back by the probe. A fitting introduction to Martian system. Of course, Mars Express was designed to image the relatively nearby surface of Mars, and not such distant objects, so the resolution of the image isn’t very good. And yet, they’re instantly recognizable as the Earth and Moon.

Opportunity Rover – the Earth from the Surface of Mars
Here’s an image of Earth captured from the surface of another planet. In this case, we’re seeing Earth from Mars, as photographed by NASA’s Mars rover Opportunity on April 29, 2005. Normally operating only in the Martian day, Opportunity woke up a little after sunset, and captured this image of Earth as the stars were starting to come out. The image of Earth looks a little elongated because it was moving slightly during the 15-second exposures. Imagine what some future Martian might see, stepping out onto the surface of the Red Planet in the dusky twilight to see our bright planet in the sky.


Rosetta – Earth and Moon during a flyby

Now this is what you might have been expecting to see. A picture of Earth, with the continents clearly visible. This photograph of Earth and the other of the Moon were taken by ESA’s Rosetta spacecraft during a flyby on November 15, 2007. Rosetta’s primary mission is to visit Comet 67P/Churyumov-Gerasimenko in May 2014, but this flyby was a great opportunity for Rosetta to test out its OSIRIS camera system. The image of the Moon was taken separately.


Earthrise – seen from the Moon
This is the classic “Earthrise” photograph, captured by astronaut William Anders during the historic Apollo 8 mission – the first human mission to the Moon. This photograph was taken on December 24, 1968. If you’re standing on the surface of the Moon, the Earth doesn’t actually “rise”. Since the Moon is tidally locked to the Earth, our planet always hangs in exactly the same point of the sky. It takes an orbiting spacecraft to see the Earth actually rise from the horizon.

This photograph was recreated by the Japanese Kaguya spacecraft, which captured a similar sequence of the Earth using its high-definition video camera.

Earth from Galileo
And finally, I think I’ve saved one of the best pictures for last. This is a photograph of the Earth and Moon (not to scale) captured by NASA’s Galileo spacecraft as it was speeding away towards Jupiter. Galileo captured these images in 1992, and finally reached the Jovian system in 1995-97. You’re looking at the Pacific Image, with South America visible as well as the Caribbean.