The Blood Moon Rises Trivia Quiz

Answer: Eclipse

The obscurity is temporary and, as stated, it occurs when the celestial body (astronomical object) passes into the shadow of another body. Alternatively, this is also noted when another body passes between a viewer and the object that they are observing.

A good example of this is a lunar eclipse, which will occur when the Moon moves into the Earth's shadow. However, this will only occur when the Sun, the Earth and the Moon are closely aligned and the Moon is full. This alignment will cause the Moon to darken or appear to go red in colour causing the effect to be labelled a "blood moon".

Answer: Transit

The important point to note here is that a "smaller" celestial object is passing between the viewer and another "angularly larger" celestial object. It stands to reason then that the smaller object will obscure a fraction of the larger one from the viewer. The opposite of this is called an occultation.

Good examples of a transit that can sometimes occur are, when viewed from the Earth, the planets Mercury or Venus moving across the face of the sun or the moons orbiting their host planets.

Answer: Ellipse

The above definition is directly from the Merriam-Webster online dictionary but, to put it another way, it is often called an oval or a two-dimensional shape that looks like an elongated circle. There are two axes on an ellipse, the widest distance being the major axis and the shorter, the minor. There are two foci (plural of focus) on the major axis, and these have the same distance from the widest points. As a consequence, the sum total of the distances of these two foci will remain constant.

So why are ellipses important to astronomers? During the 17th century Johannes Kepler identified that planets orbit in an ellipse, dispelling the belief that their orbits were a perfect circle. This also indicated that the sun was one of the focus points of the ellipse, not at the centre. Armed with this knowledge, astronomers can accurately calculate and predict the positions of planets and moons, as well as comets. They are also essential in the planning stages of space missions and determining how much fuel will be required.

Answer: Photometry

The reason for "a science", rather than "the science" in the above definition is that there are various types of photometry. Basically, it is the art of measuring the intensity of light photons that are being radiated by any celestial object. This allows scientists to measure a range of the object's characteristics, such as temperature, any changes in brightness and its colour.

The method involves passing the light from the object through a series of passbands (specialized filters) and capturing the result on devices such as a camera CCD (Charge-Coupled Device). Different passbands are used to cover different wavelengths such as infra-red or ultraviolet, for example.

Answer: Umbra

The above definition is specific for eclipses as an umbra can also be the dark inner region of a sunspot. To illustrate an umbra, we'll use a solar eclipse as an example; if you were situated in the umbra, you would be able to see the disc that is the Sun completely covered by the Moon.

However, if you were in the penumbra (the less dark outer shadow), you would only be witness to a partial eclipse by the Moon. There is a third member of this group, the antumbra. If the eclipse you were observing was an annular solar eclipse [where the covering object (the Moon) is smaller than the object it is obscuring (the Sun)], then you are said to be in the antumbra.

Answer: Solar Eclipse

For this event to occur, the three, the Earth, the Moon and the Sun will need to be in a straight line.

There are three types of solar eclipse:
Total - when the Moon completely obscures the Sun.
Partial - in a similar vein, when the Moon only obscures a part of the Sun
Annular - this will occur when the Moon is further away than it is on average, hence making it appear smaller than it is. In this event, the Sun will remain visible, appearing as if it is a solar ring around the Moon.

Care should be taken not to view a solar eclipse with the naked eye as the Sun's ultraviolet and infra-red rays will become more intense and will cause retinal damage called solar retinopathy. Essentially, the rays will burn retinal tissue, and this will cause blurred vision or create permanent blind spots.

Answer: Occultation

The above definition is complete in its own right however, the question on your mind is, most likely, what is the difference between an eclipse and an occultation. The eclipse involves three bodies (rather than two) and it occurs when one of those bodies passes into the shadow of another. The Moon passing in front of, and temporarily hiding, distant stars is an example of occultation.

Scientists find occultations extremely useful in studying the atmospheres of objects in the Kuiper Belt. For example, when a star is obscured by one of the Belt's icy objects, the light from the star will pass through that object's atmosphere, be imprinted with its spectral signature and carry it through to the Earth.

Answer: Light Curve

Aside from brightness, the light curve can also be used to observe both the magnitude and the colour of the same object over time. These are foundational astronomical tools that enable scientists to study a range of celestial objects such as exoplanets, binary systems, super novae and variable stars, that are too far away to resolve into images.

The information they can garner from these would include the make up or nature of the object, its energy sources, and how it might function.

Answer: Shadow

Not much else needs to be added to the above definition, except to say that the shadow will always point away from the source of light. A good example is the Moon's shadow being cast on the Earth during a solar eclipse.

Answer: Exoplanet

Also known as an extrasolar planet, the first theories about their existence arose during the 16th century. Cosmological philosophers, such as Italy's Giordano Bruno, put forward the notion of an infinite universe that contained other planets revolving around stars. Similar suggestions emerged from the likes of Isaac Newton in the 18th century and, not long later, observational research was entered into.

The first exoplanet to be discovered was Dimidium, uncovered by the Haute-Provence Observatory in 1995. This opened the floodgates and thousands of exoplanets have since been added to the list.