Space, the final frontier. We live on just one of the hundred billion planets floating around the hundred billion solar systems floating around the hundred billion galaxies floating around in the universe (or universes?). Us Earth-folk, therefore, are really only seeing an almost infinitesimally small slither of the universe. However, that doesn’t mean we can’t see some seriously spectacular things up in our part of the sky every now and then. Far from it. Below is a list of astronomical events and space objects that make for amazing sightings down here on Earth if you happen to spot them when they occur or fly overhead. How many of these can you spot in one night? Good luck and happy stargazing!
1. The International Space Station.
By far the most easily visible artificial satellite from Earth, the ISS is so bright it can actually become the second or third brightest object in the sky at night. The Station orbits the Earth about every 90 minutes, making sightings from everywhere on Earth a frequent occurrence. The NASA-created website, Spot the Station, can give you information as to when a flyby is scheduled to occur over your area and how long the Station will likely be visible for.
2. Iridium flares.
An iridium flare occurs when a communications satellite reflects light from the sun back onto Earth at night, causing it to light up very brightly for brief periods of time. As many as three or four flashes can occur during any given night, making them a common, yet nonetheless mesmerizing, sight for astronomers amateur and professional alike. The iPhone app, Sky Guide, gives a helpful list of where iridium satellites are in the sky and when an iridium flash is slated to occur, if you're looking to seriously amp up your stargazing game.
3. Meteor showers.
Chances are you once found yourself in a lawn chair in the middle of the night hunting for meteors during your childhood, but it still remains one of the more fun astronomy-related activities you can do without a telescope or binoculars. Watching a small piece of space junk fry up into spectacular oblivion sure beats the stale, "gee, the moon is awfully bright tonight" talk of old, especially if you manage to see several in one sitting. The best meteor showers are the annual Perseids and the Geminids, which peak August 12 and December 14, this year (2016).
4. Eclipses.
Eclipses are spectacular -- the problem, though, is that they don't happen all that often. A lunar eclipse occurs when the Earth falls directly between the Sun and the Moon such that the Earth's shadow completely blocks the Moon, thereby turning it a dark red color. It's easy to see why this happens more frequently than a solar eclipse, which occurs when the Moon completely blocks the Sun and blocks a small area of the Earth from sunlight for a few minutes. The United State's next solar eclipse (which, let's be honest, is the more visually appealing eclipse) will occur on August 21, 2017, in a fairly narrow area that spreads from South Carolina to Oregon; however, if you live in Central Africa, you'll have a chance to see a solar eclipse this year on September 1. If you're living in Europe or Asia, you'll have to settle for a partial lunar eclipse, which will occur on September 16 this year. (Note: Be sure to wear very strong eye wear when viewing a solar eclipse -- often sunglasses aren't enough to protect your eyes from the brightness, even though the Moon is blocking most of the sunlight.)
5. Planets at opposition.
Seeing most of the planets up in the night sky is routine. However, the best times to see them are when they're at "opposition," meaning they occupy the exact part of the sky opposite of where the sun is, thereby enhancing their visibility. At the time of this writing (the very early hours of June 4), Saturn is at opposition, meaning tonight is the best night since May 13, to catch a glimpse of the planet before it hits opposition again on June 15, 2017. The next planet to be at opposition will be Neptune on September 3 -- if you've ever wanted to see the most distant planet (sorry Pluto) and have a fairly strong telescope handy, that'll be your best chance. Many astronomy-related websites such as Sky & Telescope have full listings of the planets' oppositions for the next decade or so.
6. Other random cool things that happen in the sky.
Though the aforementioned events and objects are more common occurrences in the sky, that certainly isn't all that can be seen. Comets, such as the famous Halley's Comet (mark your calendars for July 28, 2061, everyone!), occasionally light up the night sky in spectacular ways; there are actually several comets that are visible right now from Earth, but you'll need a pretty good telescope to spot them. Galaxies, such as the Milky Way's next-door neighbor Andromeda, can also easily be seen with a pair of binoculars, or with the naked eye on a clear night. And finally, legend has it that the Hubble Space Telescope can be visible from Earth under ideal conditions. I personally have experienced nothing but failure in trying to see it, but several websites and smartphone apps (including the previously mentioned "Star Guide") will let you know where you need to be and at what time in order to see it. If you manage to spot it, major kudos to you.
A passing of the HST can be seen in the form of a faint white line just below the center of this photograph.
