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Canon EOS SL1 (100D) Review

I took a series of test images using a new Canon SL1 (100D) for comparison to test images of other Canon DSLR (1.6 crop factor) APS-C models popular for astro imaging. Comparison tests below also include those for a Full Frame Canon 6D. The test images include long exposure dark frames in bulb mode. Some … Read more

Logitech Fusion Webcam

Enabling Long Exposures: One of the video capture softwares I tried with the Fusion, IC CAPTURE, is being used by J-P Metsavainio to take long exposure images of a few seconds in length. J-P estimates the length of the exposures at between 1 and 4 seconds and it allowed him to take images of planetary … Read more

Which Planets Have Phases Like the Moon?

Did you know that Mercury Venus Mars and Earth all have phases similar to the Moon? And did you know that Saturn has moons too? You might be surprised to know that the Apollo astronauts were able to view Earth’s phases while on the Moon. So how do you find out which planets have phases … Read more

Which Planets Have We Visited Or Explored?

Have you ever wondered what it would be like to live on another planet? Whether you’d live on Mercury or Mars this article is for you! We’ve covered the most important planets in our solar system from Mars to Neptune. But which other planets have we visited or explored? Here are a few of them. … Read more

Which Planets Have a Solid Surface?

You may be wondering which planets have a solid surface. If so you can read on for more information. This article includes information about Earth Uranus and Neptune. It also includes information about Ganymede another moon of Jupiter. The answer to the question will surprise you! You may have never heard of this moon and … Read more

Which Two Planets Have No Moon?

You might wonder – which two planets have no moon? Mercury Venus Uranus and Neptune? In this article we will take a closer look at each planet to help you answer that question. You will learn what each one is best known for and which one is most similar to the other. Find out if … Read more

Which Two Planets Have Only One Moon?

Have you ever wondered which two planets have only one moon? The answer may surprise you. Here you will learn which two planets are most like Earth. They have similar orbits but are not as close to the Sun. This would normally give them a higher chance of having a moon. But Venus does not … Read more

Which is the Correct Way to Say ‘This’?

In the English language which is the correct way to say ‘this’? It can also be ‘that’. If you’re unsure read our article on which is the correct way to say ‘this’. We will also discuss how to use a non-restrictive clause in sentences. Finally let’s talk about the relative clauses which are inserted at … Read more

Which of the Nine Planets is the Largest?

Of all the planets in our solar system which is the largest? Saturn Earth Neptune Jupiter and Uranus all have different sizes and mass. So how do you know which is the largest? The answer is a combination of factors but in general the largest planet is the Earth. In this article we will cover … Read more

Why Two Planets Have No Natural Satellites

You may be wondering why two planets have no natural satellites. Moons are simply extraterrestrial objects that orbit around other planets. The two innermost planets Mercury and Venus are the only known planets without moons. The outermost planets such as Jupiter and Saturn have many moons. Dwarf planets such as Pluto Ceres and Neptune have … Read more

How Do the Planets Rotate Around the Sun?

Most of the planets revolve around the sun counter-clockwise though some of them have an erratic or steep tilt to their orbits. Even those that have a steeper tilt tend to maintain elliptical orbits. For example Pluto’s orbit sometimes places it between Uranus and Neptune. Mercury’s orbit is only seven degrees tilted on its elliptical … Read more

The Asteroid Belt – The Difference Between Jupiter and Mars

In this article you will learn the differences between Jupiter and Mars the two largest planets in our Solar System. You will also learn the zones and sizes of the asteroids in the asteroid belt and the rates at which asteroids may impact Earth. In addition you will learn why it is so important to … Read more

Which Force Causes Planets and Comets to Orbit the Sun?

You’ve probably heard that gravity is responsible for the motion of planets and comets but how does that work? We’ll look at two different forces involved: centripetal motion and Newton’s universal law of gravitation. What do these three forces have in common? Let’s explore them one by one. Which one is most important to our … Read more

Which Planets Can Be Seen With the Naked Eye?

In this article we’ll talk about which planets are visible to the naked eye. Later this month the five naked-eye planets will reunite for an hour after sunset. Then over the next two weeks they’ll be visible again for a half-hour each night. Until then though you’ll have to look up from your computer screen … Read more

Which Planets Can Never Be Seen at Opposition?

There are several factors to consider in determining which planets can never be seen at opposition. In this article we will talk about their geocentric longitudes appearance cycle and apparent stationary point. We will also look at their orbital declination. This information will help you determine the exact position of the planets during the opposition … Read more

How Many Planets Are in Retrograde Right Now?

If you’re wondering ‘How many planets are in retrograde right now?’ you’ve come to the right place. Here’s a list of planets in retrograde motion and their next movement. Mercury Venus Jupiter Saturn Chiron and Uranus are also in retrograde motion. Each has a different direction of movement and their respective times are shown below. … Read more

How Many Planets Are in the Universe?

Whether you’re curious about Pluto or the origins of our solar system you’ve come to the right place. Here’s a brief rundown of exoplanets from the first confirmed ones discovered in 2009 to the latest. The majority of these planets were detected indirectly. Some of these have been observed directly by scientists while others were … Read more

How Many Planets Exist in the Universe

In July 2021 humans discovered 4424 exoplanets with another 7576 candidates awaiting confirmation. To qualify as a planet an object must meet three criteria: it must be in direct orbit around a star be massive enough to crush other material in its neighborhood and have cleared the area of its orbit of other matter. Dwarf … Read more

How Many Planets Have Rings?

If you’ve ever wondered how many planets have rings you’re not alone. Saturn is not the only ‘giant’ planet with rings. Neptune and Uranus also have rings but scientists don’t know how many they all have. It’s thought they range from 500 to a thousand. Jupiter however has four known rings. And scientists don’t even … Read more