Women With Impact: Lunar Craters Named After Women

The International Astronomical Union is the world’s foremost authority on the naming of astronomical objects, including the Moon and its features. There are various systems and protocols for naming these objects.

For example, the craters on Pluto are named after scientists who significantly contributed to the study of Pluto. There are more unusual themes, like craters on the asteroid “Eros” which are named after figures like Casanova, Lolita, and Madame Bovary, following an obvious theme. All the features on the planet Venus are named after women. Craters over 20km wide are named after deceased women who made significant contributions to their field, and those less than 20km are given generic women’s names. Other features are named after goddesses and other female mythological figures.

Despite Venus being reserved for them, women are seriously underrepresented on what many would agree is our night sky’s most impressive sight: the Moon. The sheer size it occupies in the night sky sets the Moon apart from an object like Venus and each named feature on the Moon carries a significance that you don’t get with other astronomical objects. There are over 1600 lunar craters named after humans yet only 33 of these are named after women.

Hypatia of Alexandria, who lived between 355 and 370-415 is the earliest woman in history with a crater named after her. She was one of the first known women to have made major contributions to the study of astronomy, math, and philosophy. Her father, Theon, was also a scholar and the last member of the Museum of Alexandria (connected to the Library of Alexandria) before it was destroyed. Book III of Theon’s version of Ptolemy’s Almagest established the Earth-centric model for the universe that wouldn’t be overturned until the time of Copernicus and Galileo. Many scholars today believe this was actually the work of Hypatia. Aside from astronomy and math, Hypatia was a well known philosopher and regularly gave public lectures to large crowds. This unfortunately led to her death as she was executed for preaching non-christian philosophy.

Dorothy Vaughan (1910-2008) is the most recent woman to have a lunar crater named after her. She was hired by the National Advisory Committee on Aeronautics (which later became NASA) in 1943. They didn’t originally hire African Americans but changed the rule during WWII due to account for the increased workload that the war effort demanded. She worked in the segregated West Area Computing Unit. Dorothy Vaughan was quickly promoted, becoming head of the West Area Computing Unit from 1949 until 1958, becoming the first African American to have a managerial role in the organization. When NACA transitioned to become NASA in 1958 she made the move and became an expert in FORTRAN programming. Beyond her technical skills Dorothy Vaughan was described as a steadfast advocate for the people she worked with. Just like Hypatia of Alexandria, Dorothy Vaughan made a huge impact in her field despite facing adversity at every turn.

In the time between Hypatia and Dorothy Vaughan there have been a number of notable women whose careers and accomplishments have been recognized with a lunar namesake.

Take Annie Jump Cannon (1863-1941) as an example. She developed the Harvard Spectral System. She was known for her speed at classifying stars and was credited with classifying 5,000 stars per month from 1911 to 1915. She continued on to catalogue about 350,000 stars over her lifetime. She was also a prominent advocate in the women’s suffrage movement. She had a lunar crater named after her in 1964, and you can likely see it with a backyard telescope. It’s called “Cannon” and it’s located near the east-northeastern limb of the Moon’s near side. It lies just to the northwest of the Mare Marginis, and south-southeast of the crater Plutarch.

And there is Nicole-Reine Lepaute (1723-1788), who was an astronomer and mathematician in Luxemburg. She not only has a lunar crater named after her but an asteroid as well. She did calculations for a book called Treatise of Clockmaking with her husband and another scientist named Jerome Lalande. She collaborated again with Lalande and another scientist to calculate when Halley’s Comet would return, and her prediction was accurate to within a couple of days, a major improvement on the 2 year range Edmund Halley himself was able to produce. She did calculations for Lalande’s Knowledge of the times and calculated the exact date and time of the solar eclipse in 1764. Her work went uncredited for most of her career despite colleagues like Lalande praising her brilliance and contributions to the work. Her lunar crater is located along the western edge of the Palus Epidemiarum, a minor lunar mare in the southwestern part of the Moon's near side.

It goes without saying that the number of women with lunar craters named after them doesn’t reflect the number of women deserving of that honour. Instead, it highlights the fact that throughout history women’s contributions and accomplishments have gone uncredited or been stolen. This is evident in the story of Nicole-Reine Lepaute and many others.

For the complete list of lunar craters named after women, MIT has it documented here: https://web.mit.edu/tripathi/www/lunar_women.html.

Hypatia of Alexandria’s lunar crater (actgate.com). This is on the Moon’s near side just south of the Apollo 11 landing site!

Annie jump Cannon’s lunar crater (actgate.com). This is on the Moon’s near side.

Nicole-Reine Lepaute’s lunar crater (actgate.com). This is on the Moon’s near side.

Dorothy Vaughan’s lunar crater (actgate.com). This crater is on the far side of the Moon.

References:

https://www.nasa.gov/people/dorothy-vaughan/

https://www.encyclopedia.com/people/science-and-technology/astronomy-biographies/annie-jump-cannon/

https://www.smithsonianmag.com/history/hypatia-ancient-alexandrias-great-female-scholar-10942888/

https://www.actgate.com/

The Unforgotten Sisters: Female Astronomers and Scientists before Catherine Herschel. Springer. page 121–127.

https://www.iau.org/public/themes/naming_stars/

Written by: Liam Smith

A New “Budget” Astrophotography Rig for 2024

Recently, we’ve seen a LOT of new gear hit the market, and I’ve been impressed. Just recently, ZWO released a new cooled astronomy camera for just $600 USD. SVBony, a company I first became aware of from their “junk” scopes on amazon, has since vastly improved their product line up, and is now producing an 80mm astrophotography grade telescopes for as little as $399*, and the Skywatcher Evolux 62 is currently $329*! This ASIair mini $199, which effectively replaces the computer, and allows for live stacking (leaving you with just 1 file at the end of the night to work with, instead of hundreds). If we put these all together, we can, in theory, create an amazing portable astrophotography rig, one that will rival these “SMART” telescopes like the Seestar and Origin, for years to come. *Requires field flattener (extra).

So, if I were putting together the lowest cost, yet still high quality, astrophotography rig in 2024, here’s what I would do:

[Yes, these are affiliate links, but I the costs should be the same everywhere, and All-Star Telescope offers amazing personalized support, thanks Nicholas!]

Mount and Tripod $740: Most of you know that I use a modified AZ-GTi. However, you don’t need to do this anymore, since the Star Adventurer GTi came along. This may be the highest cost item in the rig, but I believe it’s the best mount on the market today:

https://usa.all-startelescope.com/products/sky-watcher-star-adventurer-gti-mount-kit-s20595?sca_ref=2829363.lssRVxtvfU

Telescope $329 Evolux 62 (how they even make an astrophotography grade telescope at this price, I have no idea):

https://usa.all-startelescope.com/products/sky-watcher-evolux-62ed-doublet-apo-refractor-s11305?sca_ref=2829363.lssRVxtvfU

Field Flattener for this telescope (required) $269:

https://usa.all-startelescope.com/products/sky-watcher-evolux-62ed-reducer-flattener-0-9x-s20206?sca_ref=2829363.lssRVxtvfU

Camera $602: This new cooled astro camera has a smaller sensor, but also smaller pixels. You can see a detailed video on this camera at the YouTube Link below (Thanks Cuiv!): https://youtu.be/zibS7JyKdw8?si=L9GTtd2Hzcn8dOch

https://usa.all-startelescope.com/products/zwo-asi585mc-pro-planetary-colour-camera-asi585mc-p?sca_ref=2829363.lssRVxtvfU

Guide Scope and Guide Camera: No need for anything fancy here, the 30mm scope and small mono camera will work just fine.

Guide Scope $99: https://usa.all-startelescope.com/products/zwo-30f4-mini-guide-scope-zwo-30f4?sca_ref=2829363.lssRVxtvfU

Guide Camera $149: https://usa.all-startelescope.com/products/zwo-asi120mm-mini-usb2-0-mono-asi120mini?sca_ref=2829363.lssRVxtvfU

ASIair Mini $199: https://usa.all-startelescope.com/products/zwo-asiair-mini-zwo-asiair-mini?sca_ref=2829363.lssRVxtvfU

And, if you want to shoot under light polluted skies, or in narrow band, the L-eNhance is a great introductory filter $229:

https://usa.all-startelescope.com/products/optolong-l-enhance-light-pollution-filter-2-opt-l-enhance-2?sca_ref=2829363.lssRVxtvfU

All in, this totals $2,616 USD (March 2024 prices). Which is about $1,000 less expensive than a similar system I might of put together in 2022 or 2023.

I hope you found this helpful! Thanks Neil Finkle for the idea to write this blog post, and for your great emails, that ask all the right questions!

Note: If you go with the SvBony Telescope, this field flattener will work: https://usa.all-startelescope.com/products/orion-focal-reducer-0-8x-for-ed-refractors-08894?sca_ref=2829363.lssRVxtvfU

What telescope should I buy?

When someone asks me “what telescope should I buy, my budget is “X,” I usually ask questions to try to get a feel for what type of stargazer that person will end up being. Are they interested in just the Moon and planets? Or, are they looking to see galaxies and nebula from darks skies? Do they need something portable? Can they carry a large telescope or do they need something of a more manageable size?

Then, given their answers, I’ll try to match a telescope to their criteria based loosely on the chart below. I’ll also match every telescope against my personal list of minimum requirements, as follows:

1. Does the telescope have at least 4 inches of aperture (about 100mm)?

2. Does the telescope come with a red-dot or bullseye finder? (no finderscopes!)

3. Can the telescope’s mount move effortlessly left-right, and up-down and attach to the telescope with a vixen style dovetail? (No EQ mounts for beginners.)

4. Can the telescope balance precisely on the mount and stay fixed in place when released? (no camera tripods or yoke & rod mounts)

5. Can the telescope point straight up, and if it’s a refractor, does it include a 90-degree diagonal?

Note that your budget may require a slight stretch to meet these minimum requirements. If you email me asking about a telescope that is not on this list, there is a 99% chance it fails one of the above tests and I will not recommend it.

The telescopes in our “Telescope Buying Guide” are for visual observing only. I consider astrophotography a very different hobby, with very different requirements. A telescope’s ability to hold a camera has zero weight on my decision to recommend a beginner telescope for stargazing. I do have recommended gear for astrophotography, and that can be found in our “Astrophotography” buying guide.

Note:

As we move past $500, I’m trying to choose telescopes that accept 2 inch diameter eyepieces.

For non-go-to telescopes for deep-sky viewing, this chart generally follows the: “get the largest Dobsonian you can afford” rule.

Mak telescopes provide wonderful views, but their high focal lengths make viewing large star clusters challenging. Finding deep-sky objects at high magnification is often a challenge with these telescopes when not connected to a go-to system. That’s why I’ve largely restricted this class of telescope to the first column. However, because these telescopes are quite compact, I often recommend them as portable telescopes.

Some Dobsonian telescopes have finderscopes instead of bullseye finders like Telrads or Rigel Quikfinders. If you get a Dobsonian with a finderscope, you’ll probably want to upgrade to a bullseye finder. This will make finding targets much easier.

The largest factor in determining how many deep-sky objects you will be able to observe is the darkness of your skies, not your telescope. However, based on subjective analysis, I’ve found that refractors tend to perform better under light polluted skies, compared with reflectors of similar aperture.

Popular Questions for John A. Read

(This blog post is written in advance of an interview with Verywell Family Magazine)

What are some tips you can give families that want to enjoy the night sky together?

A lot of people believe you need a telescope to enjoy stargazing. That’s simply not true. You don’t need a telescope and you don’t need binoculars to enjoy stargazing. There is plenty to see with just your eyes.

The most important thing to remember is that you need to get out of the city to experience the splendor of the night sky. At least 30 minutes from the nearest city or big town if you want to see the Milky-Way.

In the days near the full Moon, the Moon is so bright, it outshines most of the stars. If you’re planning a stargazing trip, try to avoid the five days prior and five days after the full Moon.

Look for star parties hosted by your local astronomy club. There are thousands of astronomy meetups across North America each year. At these events, volunteers bring their telescopes and let the general public look through them. A quick google search is all you need to find upcoming events near you.

Do I need dark skies to do stargazing?

There are many things you can see in the night sky, even from the city. In fact, I do most of my stargazing from the city. The observatory where I occasionally work is located downtown. The brightest stars are still visible from the city. For example, if it’s winter, I can pick out the 7 brightest stars in the constellation Orion. If you live at around 45 degrees north latitude, you can see the Big Dipper asterism all year, as well as the constellation Cassiopeia (nicknamed the “Big W”. If it’s summer, you can see most of the stars in the Northern Cross (asterism), as well as the three bright stars in the Summer Triangle (asterism).

Orion Constellation as seen from the roof of a skyscraper downtown.

Burke-Gaffney Observatory - Downtown Halifax, Nova Scotia

You can also see the Moon and planets just fine from a city. These objects are not affected by light pollution.

But for most galaxies and nebulae, light pollution hides these objects even with the largest telescope. These objects require dark skies to be seen by the human eye (cameras can easily see these objects from the city, if you really know what you’re doing).

What are some fun activities you can do with your family while stargazing if you don’t have a telescope?

• Count the shooting stars. If your skies are really dark you will see several in a given night. During a meteor shower, as long as the Moon isn’t up, you’ll see about one shooting star every minute. (Shooting stars are tiny grains of dust burning up in our atmosphere).

• Count the Satellites and Airplanes. There is a LOT going on in the night sky. There are thousands of satellites just a few hundred miles overhead. These are zooming around the Earth at around 17,500 MPH (any slower and they’d fall back to Earth). You can tell the difference between a satellite and an airplane by the speed (satellites appear to move faster) and the fact that airplanes always have blinking lights on them. Satellites are simply reflecting sunlight, and often disappear when they enter Earth’s shadow.

• Learn the Constellations visible during that season. Each season brings a new set of constellations and asterisms to the evening sky. In summer, you have the “Teapot” asterism, and Scorpius constellation (or Maui’s fish hook). In Winter, you have Orion, the Hyades (star cluster in Taurus), The Greater Dog. In fall, you have the great square in Pegasus, and in Spring, you have Leo the lion, and Boötes, which looks like a giant ice cream cone. It helps to have a guidebook like 50 Things to See with a Telescope – Kids, or Learn To Stargaze for Kids, to help you identify these stars.

Two Summer Constellations from the book Learn To Stargaze for Kids.

Summer Constellation and Summer Asterism maps from Learn To Stargaze For Kids.

• The most important thing is to put away any electronic devices (screens kill your eye’s ability to see the stars). And enjoy spending time with, and talking with your family. Stargazing is often a catalyst for amazing conversations.

• I know I said no devices, but a really fun thing to do is to watch the space station or one of SpaceX’s Starlink Satellite trains pass overhead. There are apps you can get on your phone to tell you when these events occur (its generally several times per week), and going to observe these events can be a lot of fun.

What stargazing apps do you recommend?

It’s important to note that using a phone or other devise limits your eye’s ability to see the stars. It takes 20 minutes for your eyes to adapt to the dark so that you can appreciate the spender of the Milky Way. If you look at your phone to try to identify a constellation, then you have to wait another 20 minutes for your eyes to adjust again. The only reason I use stargazing apps is to learn the location of planets like Jupiter, Mars, Saturn, and Venus. I do this before I go stargazing, using a free app called Stellarium, which is available on all devices.

How do you identify the stars and constellations?

My kids and I have red headlamps, these are about $10 on Amazon, and sometimes they come in packs. These help preserve your night vision (as long as you don’t shine them in each other’s faces). The headlamps can be used to see where you’re walking, and to read the stargazing guide books like Learn To Stargaze for Kids or 50 Things to See with a Telescope - Kids, which are designed specifically to be readable under red lights.

I want to buy a telescope for my child, what telescope should I buy?

It’s important to note that telescopes, in general, are precision scientific instruments. Using them correctly requires some skill. How much skill they require depends on the telescope’s design. For example, dobsonian telescopes are generally pretty easy, whereas any telescope with EQ in the name tends to be incredibly challenging. Telescopes with AZ in the name can be easy or difficult to use depending on the design. If the telescope is mounted on what looks like a simple tripod (like most telescopes marketed at kids), it’s probably near impossible to view things high in the sky. When you’re buying a telescope for a child, parents have to realize that they’ll probably have to learn to use the telescope to locate objects first, then let the child see the object through the eyepiece.

If you go on Amazon and search for “kids telescopes”, you will not find any capable of providing decent views of the night sky. I’m pretty sure most of the reviews are fake, too. Almost all of the telescopes on Amazon targeted at kids are just toys, or what I call “bird feeder” telescopes. They’re not designed to point at the sky, and they’re not designed to track objects as they move across the sky. Sky and Telescope magazine calls these “Hobby Killers”, and there are a LOT of them on the market.

I have a set of requirements for any beginner telescope:

1. Does the telescope have at least 4 inches of aperture (about 100mm)?

2. Does the telescope come with a red-dot or bullseye finder? (no finderscopes!)

3. Can the telescope’s mount move effortlessly left-right, and up-down and attach to the telescope with a vixen style dovetail? (Dobsonians are great but no EQ mounts for beginners.)

4. Can the telescope balance precisely on the mount and stay fixed in place when released? (no camera tripods or yoke & rod mounts)

5. Can the telescope point straight up, and if it’s a refractor, does it include a 90-degree diagonal?

What should I look for in a telescope for kids?

Basically, you want a telescope that is trivially easy to use for both kids and adults, and there is really only one telescope design that meets that requirement, and it’s the table top Dobsonian. You also want to make sure the telescope comes with a finder (surprisingly, some telescopes don’t include a finder, and are therefore, pretty useless).

Two telescopes that my kids find easy to use are the Zhummel Z100 and the Orion SkyScanner 100mm.

If what you see though the telescope isn’t capable of making you go “WOW” then it’s not a great option for kids.

My son (7 years old at the time) using a Z100 Telescope to see Jupiter.

What about telescopes for adults or families?

For families, a larger Dobsonian is a safe option. An 8-inch Dobsonian telescope will provide views of thousands of objects, you just have to know what you’re looking for. The new StarSense DX line from Celestron is also nice since it uses your cellphone to help you push the telescope directly to your targets. Note that only the LT series of StarSense falls into Sky and Telescope’s “Hobby Killer” category due to the poor mount. I realize that cost is a big issue for a lot of people, but the reality is that a capable telescope cost more than a few hundred dollars.

My son (6 at the time) using an 8 inch Dobsonian telescope.

There are exceptions, however, Costco has been known to carry the Omni 102AZ refractor for as low as $139 USD. As far as I know they have never included this telescope on their webpage or anywhere online for that matter. Folks have only found it by going into the store. I really like the views through this telescope. It’s also upgradable as you grow in the hobby. I made a video about this telescope that can be found here: https://www.youtube.com/watch?v=WdEh4EODjV8 . I actually know several professional astronomers who own the Omni 102AZ, and they use it as a grab-and-go telescope. They’ll use it for easy view of the Moon, planets, or even that recent comet (E3 ZTF).

I have a grid of telescope I recommend at every price point on the homepage of LearnToStargaze.com .

Using the Omni 102AZ from Costco.

What is the first object you should look at in a beginner telescope?

Definitely the Moon. The Moon is our nearest neighbor in space, it’s close enough that with a small telescope you can explore the craters, valleys, and mountains. And because of how the shadows fall on the Moon’s surface, the Moon looks completely different every night! This is why we wrote the book 50 Things to See on the Moon.

How the Moon appears in a small telescope (iPhone photo).

What is the most amazing thing you can see through a telescope?

Definitely Saturn. Saturn should be pretty easy to find in any decent small telescope. You’ll see the rings, and its largest moon, Titan.

After you’ve observed the Moon and bright planets, it’s time to move on to deep sky objects. There is a list of 110 objects called the Messier List. This is a list of 110 of the brightest galaxies, star clusters and nebulae. Seeing all 110 objects is a popular goal for beginner stargazers. (Which is what my book 110 Things to See with a Telescope is all about).

I just bought a telescope, what barlow and other accessories should I buy next?

I get this question more than any other. Here’s the thing, most people who ask this questions haven’t even used their telescope yet. They don’t know what it can, and cannot do. It’s best to become an expert at with what you have before you dive into extras. Also, barlows make objects appear larger, but they don’t make objects appear better. The resolution of your telescope is limited by its aperture (the diameter of the big lens or mirror that collects light from space).

That said, generally, the eyepiece is the first thing you want to upgrade. Sometimes a good eyepiece costs as much as the telescope. For small telescopes, I like a premium 25mm Plossl eyepiece for deep sky objects (look to pay about $60, you get what you pay for). I’ll add a 2x barlow for planets ($30). For my larger telescopes, I like a quality 20mm 2inch wide field eyepiece for observing of deep sky objects (~$300) and a 2x 2 inch barlow for planets ($100). The eyepiece generally has to be paired to the specific telescope. For example, Celestron’s Premium 5mm X-Cel eyepiece works great to provide great views of the planets with the Omni 102AZ mentioned above, but try to use this with Schmidt Cassegrain Telescope (SCT) and the magnification will simply be too high, and the planets won’t look as good.

Where can people reach you?

I’m the host of LearnToStargaze on YouTube, and I try to respond to every comment. That’s the best way to contact me if you have specific questions about stargazing or telescopes.

What are you up to these days?

I’m a Master in Space Systems Engineering Student at John’s Hopkins University. I’m actually the only person on my team who isn’t currently an Aerospace engineer. I’m on a team of six people and we’re currently designing a constellation of 8 spacecraft for detecting forest fires (note that this is a school project, these spacecraft already exist, and are already in space).

As I said, before, I’m also the host of LearnToStargaze on YouTube, and the author of the Things to See with a Telescope series. My wife and I also just purchased 26 acres of land in Nova Scotia, and we’re planning on created a designated dark sky location where stargazers can come appreciate the night sky without worrying about city lights. It’s also a place for people to come to learn to use a telescope, and have someone give them a guided tour of the night sky.

Have you ever seen a UFO?

I’ve never seen anything I couldn’t explain. If I see something flashing or moving oddly in the sky, I’ll take a photo, and record the time. Then I’ll use software to see which satellites, airplanes, or balloons are in the sky. I have ALWAYS been successful in identifying the object, and it’s always been something mundane. Identifying objects in the sky is something savvy astronomers get quite good at. This is way people who look at the sky as a profession almost never report seeing UFOs.

The most common UFO sightings by the public (including pilots) can be traced back to the planets Venus or Jupiter. These planets are very bright, and if you’re driving down a dark road at night, and the planet is behind the trees, there is an optical illusion that creates the impression that the light is following you. In reality, the planet is just so distant, that it doesn’t change position as you move.

But I saw on CNN that military pilots report seeing UFOs doing impossible things. What’s going on there?

Based on the videos and reports I’ve seen, the objects military pilots are observing most likely fall into one of five categories: birds, other airplanes/balloons, sky lanterns, lens flares, or Venus/Jupiter optical illusions. I give it a 99% probability that the objects they’re observing fall into one of these five categories, with the other 1% being something even more mundane.