Category: Urban Astronomy

Urban Astronomy – Jupiter and Venus – just after sunset

Mars, the Moon and Constellation Orion, too.

Revised for March 4,5 – 2023

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

If the sky is clear, you will find Jupiter Venus the Western sky just after sunset (1). If you manage that, have a look near overhead at Mars (2), the Moon (3) over to the East and for Extra Points, the (4) Constellation Orion. Please see revised chart for March 4, ’23, at 6:30 PM,below

All Hat and No Cattle

The comet brightness fell suddenly just as the sky cleared off. I should say that this sort of behavior is to be expected of comets. As the approach closer to the Sun, gasses evaporate straight from solid to gas (“sublimation” it is called) and the expanding cloud reflects more light than the chunk of rock and ice alone. These gasses get blown away by the Solar wind, and the comet dims again. If this did not happen, the comet nucleus would simply reflect sunlight and its “light curve” would look like the green dotted trend I calculated. I added the observed brightness for Feb 4 – which happens to fall near that curve.

Sorry to have wasted your time. – Steve

Comet C/2022 E3

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

The comet is now well-within visible range – but it will take considerable snakey-eyed concentration to pick it out. More importantly, there will be clear skies on Friday night. I put together this chart with instructions. Print it out and follow instructions. If you need light to see the chart, close one eye while you turn on the flashlight. Or, use an eye-patch to keep night vision in one eye while consulting chart. Professional Astronomers do this, while making corny pirate jokes. 😉

Hasta Luego,

Steve

Comet C/2022 E3 – Conjunction with Mars

February 9 – 12 2023

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

Read this first: https://www.timeanddate.com/astronomy/measuring-the-sky-by-hand.html

There is an “eyes only” comet currently in the Northern Hemisphere skies that will soon be near Mars.

As many of us urban dwellers can attest, “eyes only” means other people can see it.

However, if “Seeing” is good and a good reference body is to be had, binocular-equipped viewers in the worst of urban glare may well be able to pick out the comet in about two weeks and change.

  1.  Below is a sky chart from the point of view of Houston observers for February 10, 2023.  Since Mars moves slowly through the sky, this will suffice to show the relative positions of the constellations and Mars for the four-day period I am analyzing here.  The chart is calculated at 2200  (8 PM CDT) and everything will be moving to the West (right) until things start setting in the West, around 1 or 2 AM. All images credit: Heavens-Above.com
  • Once you have located Mars, get out those binoculars – or use those keen eyes if you are in dark skies.  Use the dated charts below to find where to look for the Comet.

Contact me with any questions: steve.campbell@reagan.com

Hasta Luego,

Steve</b>

Urban Astronomy – Mars/Jupiter Conjunction 05/29/22

Posted May 18, 2022

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

So, at this point, I know my audience. 

See Mars and Jupiter in Close Conjunction, Sunday, May 29 – around 5:30 AM Central Daylight Time

Sky Chart from Heavens-Above.com   May 29 at 5:30 AM CDT (UTM -5)

You can print out the chart and hold it with East at the bottom while facing East – to match up the planets with the chart.  Cloudy weather is probable, so  check in the days before and after, just in case.

Hasta Luego,

Steve

Urban Astronomy – Venus/Jupiter Conjunction 04/30/22

Posted April 27, 2022

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

So, at this point, I know my audience. 

See Venus and Jupiter in Close Conjunction, Saturday, April 30 – around 6 AM

Figure 1: As Close as It Gets

Urban Astronomy  April 19, 2022

Venus is the “skymark” for a collection of planets in the morning sky. 

  Look East before dawn to find Jupiter, Venus, Mars and Saturn lined up in the Southeast.  Jupiter is the lowest in the sky and second-brightest.  A bit higher is Venus – the brightest by far with Mars next and then Saturn.  See the sky chart below for reference.  If you print it out, the best way to use it is to hold it with “East” at the bottom and face East. 

Figure 1:  Skychart for April 19th from Heavens-Above.com

Don’t imagine that these planets are actually anywhere near each other. The diagram below should give the reader the “Big Picture”. The positions of the planets (including the one you are standing on). Figure

Figure 2: Yellow lines depict the “lines of sight” from an observer on Earth to the four planets. To give scale: The line from you to Saturn is almost a billion miles long.

Skymaps from Heavens-Above.com  

Solar System diagram from NASA Small Body Database Lookup

Ex Scientia, Trivia!

Steve

Urban Astronomy  April 19, 2022

Urban Astronomy – Comet Leonard 12/20/21

Posted December 20, 2021

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

So, at this point, I know my audience. 

Comet 2021 A1 – Leonard Dec 20, 2021

Leonard is even brighter – in fact much brighter – tonight. The current magnitude of Leonard is +2.3 (the smaller the number, the brighter – the comet was +4.6 yesterday and Saturn is +0.23 – VERY bright by comparison) so in the city, the Comet is visible and would be still better seen with binoculars. 

You may have heard the expression “by an order of magnitude”  – well this is over two orders of magnitude – OK?

Once again, do not use telescopes or binoculars to view the Sun – blindness will result!  I said “after sunset” so you should be OK if you listen to me. 😉

As is usual in these cases, the comet gets brighter not only because it gets close to the Earth.  It also gets brighter because it gets closer to the Sun.  The third brightening influence is the material that the closer sun vaporizes.  That stuff makes a cloud around the comet and is it also partially blown away by what is called the Solar Wind – in a comet’s tail.

Figure 1, above shows the location to view, which is conveniently close to Venus, which is the brightest thing in the sky.  If you can see the Planet, you should be able to see the comet – although you may need those binoculars to do so. 

The sky is currently “mostly clear” (look-out-window method) in Houston at 3:22 PM.   Sunset is at 5:26 PM.  These next few days are literally the last chance to see Leonard, as it is on a hyperbolic orbit – which is a nerdy way to say that it will never return to the Solar System.  (Please see figure 2 below)

For readers not in the Houston area, just look for Venus (and Jupiter for orientation) and use the chart in Figure one above to find the comet.  We are lucky to be able to have the two brightest objects in the sky (now that the moon is not around in the early evening) as our reference points.

Hasta Luego,

Steve

Urban Astronomy – Comet Leonard

Unmasked and Unafraid

Posted December 19, 2021

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

So, at this point, I know my audience. 

Comet 2021 A1 – Leonard

There is another “Eyes Only Visible” comet to be seen in the Southwestern sky, just after sunset. The current magnitude of Leonard is +4.6, so in the city, it is only just visible and would be better seen with binoculars.  Once again, do not use telescopes or binoculars to view the Sun – blindness will result!  I said “after sunset” so you should be OK if you listen to me. 😉

As is usual in these cases, the comet gets brighter not only because it gets close to the Earth.  It also gets brighter because it gets closer to the Sun.  The third brightening influence is the material that the closer sun vaporizes.  That stuff makes a cloud around the comet and is it also partially blown away by what is called the Solar Wind – in a comet’s tail.

Figure 1, above shows the location to view, which is conveniently close to Venus, which is the brightest thing in the sky.  If you can see the Planet, you should be able to see the comet – although you may need those binoculars to do so.  

We have had very cloudy weather here in Houston (today, Dec 19) is “Mostly Cloudy” at 4 PM, changing to “Cloudy” around Sunset at 5:26 PM.  Tommorow at Sundown the prediction is “Mostly Cloudy” and the comet will have moved slightly relative to Venus.  These next few days are literally the last chance to see Leonard, as it is on a hyperbolic orbit – which is a nerdy way to say that it will never return to the Solar System.  (Please see figure 2 below)

Figure 2. Comet Leonard is diving through the Solar System, never to return.

For readers not in the Houston area, just look for Venus (and Jupiter for orientation) and use the chart above to find the comet.  We are lucky to be able to have the two brightest objects in the sky (now that the moon is not around in the early evening) as our reference points.

Hasta Luego,

Steve