How far can we see into space? A very long way indeed. But not only are we seeing objects that are far away we are also seeing them as they existed (past tense). Why? Because as much as we would like to think light is instantaneous it actually travels at a measured or finite speed.
How fast is it? Light travels at 186,282 miles per second or roughly 300 million meters per second. Pretty darn fast but when you start talking astronomical distances the speed of light becomes apparent. Once you know the distance to an object you can then calculate how long it takes light to reach it.
The light reflected from the Moon takes 1.255 seconds to reach us here on Earth. Light emitted from the Sun takes over 8 minutes to get to us. And so on. The most distant galaxies in the Hubble Ultra Deep Field image are 13 billion light-years away.
What’s a light year? A light year is the distance light travels in a year or almost 6 trillion miles. So to get back to what I was saying about seeing these distant objects as the existed, it should now make sense to you that the farther we look into the universe, the farther we also look back in time.
Take the Andromeda Galaxy pictured above. Under a dark sky you can actually see this galaxy with the unaided eye. The galaxy is about 2.5 million light years from us. So when we look at that galaxy we see it as it existed 2.5 million years ago. Why? because it’s taken that long for the light we are seeing to make it to our telescope mirrors and eyes.
So the next time you look up at the night sky remember you are not only an observer of the stars but also a time traveler and that telescope of yours is your time machine.
I’ve been busy working on the blog site and have added a number of things that should be useful to visitors. Here’s the run down.
After having been removed several months ago due to issues it had with the WordPress site theme, the Events Calendar makes its return. You can now check on specific dates for astronomical events, star parties and much more on the calendar or give a glance at the “upcoming events” in the right-hand column on the home page. The calendar still needs to have events added but April and May are done.
Next up is both a link in the main menu and social media icons to both the Scott’s Astronomy Page Facebook Group page and Twitter accounts. The Twitter account has been featured on the site now for some time but not the Facebook Group page. I recently made the Facebook page public in order to allow for visitors of the blog site to access, join and follow the site. I have to admit the Facebook Group site does get updated more frequently than the blog. So Join, Follow and Share!
Next up is the Astronomy News page. I added this content a few months ago but didn’t really advertise the fact that I had done so. Through the miracle or RSS (Rich Site Summary or Really Simple Syndication) I’ve pulled in content (specifically astronomy and space related news and podcasts) into one page making it easy to access. I still plan more tweaks for the page as I’m not entirely in love with the look.
Then there is the new Astro Data Sets page which provides a great deal of information for folks in the Dallas-Fort Worth area. On this page you’ll find a Moon phase chart which also includes morning and evening twilight, moon rise and set and sun rise and set times all in tabular form and predicted out for the next 10 days.
Also on the Astro Data Sets page is the Planetary Data table which shows each planet and gives its rise and set times, the time the planet crosses the meridian as well as the constellation the planet is in and a visibility prediction. And if that is not enough the same page has a 10 day International Space Station prediction grid and visible iridium flares table showing those flares that can be seen in the next seven days. Again, all of this is specific to the DFW area.
Last but not least there is now a Current Sky Map page which displays the sky for the DFW area as it exists the moment you load the page. The link for the sky map is in the menu under the Astro Data Sets listing. This can be a helpful guide for you to pull up and then head outside to pin point an object in the sky.
Not in the DFW area are you? No worries. There is also a link on this page for those not in the DFW area to go to and pull up a map for their neck of the woods. This map is provided by Astro Viewer.
I enjoyed adding all this new content and welcome your feedback. Thanks for checking out the blog! Shoot me a comment and let me know what you think.
Crepuscular rays or Sun rays are rays of sunlight that appear to radiate from the point in the sky where the sun is located. These rays, which stream through gaps in clouds or between other objects, are columns of sunlit air. Despite seeming to converge at a point, the rays are in fact near-parallel shafts of sunlight, and their apparent convergence is a perspective effect (similar, for example, to the way that parallel railway lines seem to converge at a point in the distance).
The images on this page were all taken on the evening of April 4, 2017. Including this one below of anticrepusculer rays. The sun rays seen below were captured directly opposite in the sky from the picture seen above. Interestingly the rays seem to converge where there is no Sun!
As 2016 comes to a close corks will be popping and fireworks firing to be sure. But make sure in all the excitement you don’t miss the celestial fireworks!
There will be the opportunity for you to see periodic Comet 45P/Honda-Mrkos-Pajdusakova in the constellation Capricornus. This comet has an orbital period of just 5.25 years that takes out to Jupiter’s orbit before plunging back toward the Sun.
The best time to view will be just after sunset on new years eve, December 31, 2016. The south-western sky will be filled with other great objects for you to observe besides the comet including the Moon, Venus, Mars and Neptune.
The sky chart above shows Comet 45P at about 21 degrees above the horizon and roughly 5 degrees away from the Moon. This will make for great viewing with binoculars or a telescope.
In early February this comet will pass within 0.1 AU of the earth. It is predicted to reach maximum brightness of magnitude ~7 in early January.
Below is a broader view of the same area of sky on 12-31-2016 showing the other planets, Venus, Mars and Neptune which will also be visible.
Mars and Neptune will be mere 0.2 degrees a part and visible in the same field of view of a telescope. Use high power eyepieces on Neptune to see it’s small blueish disk. Mars’ red color will be easily discernible.
Shining brightly at -4.4, Venus will be the show stopper. Known as the morning or evening star, as it never wanders far from the Sun from our vantage point, seen through a telescope Venus will appear as a gibbous disc that is about 60% sunlit.
So while the party is going on slip out into the cool or cold night air and view the big show of planets and comets. And take note, these celestial orbs will be setting about the time to red orb drops in NYC.
The park is located 50 miles west of Fort Worth. This very popular family friendly star party (average attendance of 200) is hosted by Lake Mineral Wells State Park and Dr. Mike Hibbs of Tarleton State University.
The North Texas Skywatch Star Party will start at 7:00 PM and last as long as observers want to stay up. The intent is to give the residence of the North Texas a nearby meeting place and dark sky location to get together. “I hope that all of those with telescopes can stay and share views through their telescopes, or knowledge of astronomy, to those wanting a chance to learn and see for the first time.” The only cost is the normal State Park admission. You will be able to camp out for the night if you want. Come early and enjoy the park and have a cookout. Lake Mineral Wells State Park is about 50 miles west of Fort Worth off of HWY 180. Contact the Park for the entrance and camping fees and reservations.
Here we are less than 365 days until the total solar eclipse that will be seen from coast-to-coast in the U.S. on August 21, 2017. This will be the first total solar eclipse to grace the U.S. mainland since 1979 and the first to sweep across the entire country since 1918!
Before I go any further I want to say to all those reading this article who have never witnessed a total solar eclipse – please, please make every effort to get to the center line next summer and experience totality. Nothing compares to it. No words can adequately explain the awesome spectacle, the emotional response generated and grandeur of a total solar eclipse. You simply must experience it at least once in your lifetime.
Okay, now that I have that off my chest let me start by just being honest and upfront – eclipses are addictive! Watch one and you will probably find yourself gravitating to all the subsequent solar and lunar eclipses on the calendar. Eclipse chasers as they are called share a close bold with gold prospectors. Once the fever gets in your blood watch out, as you’ll be hooked for life. That is not a bad thing.
Now is the time to act! But wait?! The eclipse is a year away. Yes, it is but now is the time to plan your trip and make your travel arrangements. Is there a relative of yours that lives near the center line? Can we make a trip as a family to see this event even though it will take place right around the time many schools will be starting up, etc. There is work to be done to ensure you have all your bases covered and your plans ironed out. You do not want to wait until one, two or three months out to start making your travel plans. Trust me.
So as we proceed to countdown the days, weeks and months to what will most assuredly be referred to as “the great solar eclipse of 2017” I will be posting about this astronomical event and offering up important and timely information. My goal is to provide this information from a helpful perspective coming from an amateur astronomer who has seen a total solar eclipse with his own eyes and lived to tell about it.
So to recap, make your travel plans now for this eclipse. Do not wait. Now is the time to beat the masses and the last minute chaos and stress that goes with it.
Here are some helpful resources as you plan for the total solar eclipse of 2017.
The 2017 Total Solar Eclipse podcast – All about the upcoming total solar eclipse that will sweep across the U.S. on August 21, 2017. Listen to new programs and eclipse topics each week.
Prepare for Totality 2017 is Astronomy Magazine’s page offering an interactive solar eclipse map of the path of totality (zoom in and out), eclipse facts, trip advice, helpful products, solar eclipse glossary, intro to safe solar viewing video as well as a free e-guide for download on the 2017 total solar eclipse.
2017 Solar Eclipse Prime page – Fred Espenak “Mr. Eclipse” detailed discussion on the total solar eclipse of 2017. Your one stop shop for maps and information.
NASA’s Eclipse web site – This special web page contains preliminary information about the 2017 total eclipse of the Sun. It will be updated with more information as eclipse day approaches.