Take a Deep Dive into Deep Space

   Take a deep dive into deep space at the DESI Legacy Imaging Surveys web site. This is an interactive display using a 10 trillion pixel composite picture of much of the night sky, based on different imaging data sets to create the image. The zoom-in is incredible as the billions of points of light resolve into galaxies, nebulae and other deep sky objects. Some of the datasets even show a spectral display. There are a number of ways to interact with the images including a way to flip back and forth between two images to watch for any objects in motion. Clicking on the screen will bring up options for joining a forum to ask or discuss what you are viewing. There are links to other information about that object or part of the sky.
   The video is a short tour of around Taurus and Orion.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

Crescent Moon – Neptune Conjunction

   Saturday February 13th the 2-day old thin waxing crescent Moon will be about 2-3o from the outer planet Neptune and about 6-7o to the west from Dwarf Planet Ceres. The Moon will pass by Ceres over the next 24 hours and by about this time tomorrow the Moon will be to the east from Ceres.
   I should point out that Ceres with an apparent magnitude between 8th and 9th and Neptune with an apparent magnitude between 7th and 8th neither will be visible to the unaided eye.
   However when you are looking toward the Moon you will be looking in the direction of these two distant members of our solar system. This graphic shows the position of the Earth, our Moon, Ceres, and Neptune on February 13th. From this perspective objects to the left of the Sun will be seen in the evening skies as the Earth rotates.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

Springtime on Mars!

A Martian Year

A Martian Year – at One Earth Month Intervals

   Four days ago, February 2nd, we ‘celebrated'(?) Groundhog Day where in the Northern Hemisphere if the groundhog sees its shadow there will be 6 more weeks of winter. Coincidentally on Saturday February 6th it is the spring equinox on the planet Mars as the planet transitions from its winter season to spring during its 684 Earth day orbit around the Sun. However there are no groundhogs on Mars! So there may be clear skies but given daily temperatures on the Martian surface to me it looks like spring time all the time, albeit rather cool!
   Seasons on Mars are marked by the planet’s heliocentric longitude coordinates using the position of Mars along its orbit around the Sun. Each seasonal start/ending point is 90 degrees apart, but because of its elliptical-shaped orbit each Martian season is of varying lengths.

   I’m not exactly sure why this particular date is used but by international agreement astronomers have selected April 11th, 1955 as 0 degrees for year 1 of this Martian calendar. What this works out to is that on Saturday February 6th, Earth time, it is the start of spring for year 36 using the aforementioned calendar system.

Year 35
0 degrees — Spring Equinox — March 23 2019
90 degrees — Summer solstice — October 08 2019
180 degrees — Fall Equinox — April 08 2020
270 degrees — Winter Solstice — September 02 2020

Year 36
0 degrees — Spring Equinox — February 06 2021
90 degrees — Summer solstice — August 25 2021
180 degrees — Fall Equinox — February 24 2022
270 degrees — Winter Solstice — July 21 2022

Learn a little (or a lot) more about the exploration of Mars at the NASA Explore the Moon to Mars website.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

February Moon at Descending Node

   Saturday February 6th the 25-day old waning crescent Moon crosses the plane of the ecliptic moving south. This is known as the descending node, one of two intersections the Moon’s orbital path (dark green line) has with the ecliptic.

   On the date of the descending node the 25-day old thin waning crescent Moon will be over the eastern horizon at sunrise local time.

   
   
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

February Moon at Perigee & Spica Conjunction

   Our Moon reaches perigee, (closest to Earth), for this orbit, on Wednesday February 3rd. At that time the Moon will be at a distance of 28.8 Earth diameters, 229,986 miles (370,127 km) from the Earth.

   Before sunrise on the date of the perigee Moon the 20.4-day old waning gibbous Moon and will be about 7-8o from the star Spica in Virgo the Harvest Maiden.

   Does our Moon actually go around the Earth as this graphic shows? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*
   *Click here to read my Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

   
   
   
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.


Also Follow me and other great resources at Feedspot.

Imbolog 2021

   Watch That WoodChuck!
groundhog newspaper   On February 2, we watch for the groundhog to emerge for reasons that originate from ancient Celtic tradition. Groundhog Day was known as lmbolog, or sheep’s milk, a time for nurturing young sheep and planting spring crops. The belief arose that if lmbolog were to be sunny and clear, then winter’s effects would endure, foreshadowing a long winter. How­ever, if skies were overcast, then the warmer days of spring would arrive early. To farmers then and today, an early spring means early spring plant­ing and a subsequent early harvest. Often fires were lit to commemorate the event as fires were a sign of warmth and light, both of which increased as days lengthened.
not a meteorologist   German immigrant farmers are credited with bringing Groundhog Day with them to the United States as they settled in Pennsylvania. To them, February 2 was called Candlemas Day, because of the practice of lighting candles on this day in celebration of early planting. The Germans believed that the badger was able to predict the weather on the basis of whether or not its shadow appeared. If the badger, or groundhog, saw its shadow on Candlemas, it would be scared and return to its burrow for another six weeks to sleep through the long winter. However, if the skies were cloudy then no shadows would appear, and an early and warm spring would be expected. The importance of this day to German immigrants, and its impact on their farming gave rise to the couplet:
         A farmer would rather see his wife upon a bier,
         than that Candlemas Day should be sunny and clear.

puxs-phil-lied   Year after year, since 1898, crowds have gathered in Punxsutawney, Pennsylvania, on February 2 to wait for a certain groundhog to emerge from its burrow. Today the belief in this as a predictor of weather is not nearly as consequential as it appears despite all the hoopla created by the news media. Yet, there is some scientific rationale to this ritual, albeit not in the accuracy of the forecast. When the skies are clear, temperatures tend to be cold as the ground radiates heat absorbed during the day back into the atmosphere; and when skies are over­cast temperatures tend to moderate as clouds trap heat nearer the ground.
Midpoints
Groundhog-Standing2   To other cultures in the Northern Hemisphere Candlemas Day was celebrated as the midpoint, or cross­ quarter day, between the winter solstice and the spring equinox. Cross-quarter days occur midway between the astronomical events that mark the beginning of each of the four seasons, the solstices and the equinoxes. The second cross-quarter day of the year, as it is calculated mathematically, occurs on May 6, although it is often associated with May Day, on May 1. The third cross­ quarter day of the year is August 7, the only one of the four without a significant event associated with it. Mid-autumn, the fourth cross-quarter day, occurs on the last day of October, Hallowmas Eve, or as we now know it, Halloween.
   Interestingly this system of equinox, solstice, and cross-quarter days has led to some confusion as to when the seasonal midpoints and endpoints occur. For example, June 21-22 is the official date for the start of summer in the Northern Hemisphere, but it is sometimes referred to as midsummer’s day. This would suggest that summer actually begins on May Day and ends in early August. In a similar manner, December 21, the start of winter for the Northern Hemisphere, is some­times referred to as midwinter’s day. This would imply winter actually begins at the end of October, and concludes (assuming no shadow is seen) on Groundhog Day.
groundhog   So will we have a long winter, or will it be short, and our spring be an early spring? No one can predict this, at least not based on seeing one’s shadow. However, come this February 2, rest assured that crowds will once again gather to watch Punxsutawney Phil emerge from his hole.
   Adapted from “Watch that Woodchuck” Scope on the Skies. Science Scope Magazine. February 1993.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

Mars at Eastern Quadrature

orbital-positions   Monday February 1st the position of the planet Mars, with respect to the Earth and the Sun, places this planet at what is called eastern quadrature. At that orbital position Mars, and actually any outer planet, is at a 90 degree angle from the Earth as this graphic shows, and the banner graphic at the top of the page shows. Think first quarter Moon as that is a fair comparison of the relative positions of Earth, Sun, and Mars.

   At this position Mars follows the Sun across the sky from east to west as the Earth is rotating, meaning that Mars rises after the Sun and then sets after the Sun. Mars, with an apparent magnitude of 0.45, is about 5o from the 5.8 magnitude Uranus.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

Leo, the Moon, Mars, Mercury, and a Ram

   No, that is not the opening line to a “walked into a bar…” joke, but rather an example of trying to fit 4 different topics into one title!
Read on.

   Friday evening January 29th the 17-day old waning gibbous Moon will be about 4-5o from the star Regulus. This star is known as the ‘Heart’ of the constellation Leo the Lion.

   Mars is visible further west over the southwest horizon and is a few degrees from the planet Uranus. Both are near the 3-star pattern for the constellation Aries the Ram and its brightest star Hamal with a 2.0 apparent magnitude. The two planets have a sharp contrast in relative apparent magnitude with Hamal and with each other – Mars at 0.40 and Uranus at a 5.80 apparent magnitude. Both planets will fit within the field of view of binoculars with Mars appearing as a small reddish ‘dot’ and Uranus, if seen at all, a much fainter bluish-green and smaller ‘dot’.

   Earlier in the evening, after sunset, look toward the western horizon for the innermost planet Mercury. With an apparent magnitude of 0.45 Mercury is slightly dimmer than Mars and should be easy to spot as it will be the brightest star-like object in that direction.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

The Twins Point the Way

   Wednesday evening January 27th the nearly full Moon, a 14-day old waxing gibbous Moon, will be about 6-7o from the star Pollux, one of the two twin stars of Gemini the Twins. The other ‘twin star’, the other brother, is Castor.

   Off to the west over the southern horizon are the planet Mars and Uranus. Further west is Neptune, and the Dwarf Planets Eris and Ceres. Earlier in the evening, after sunset local time the innermost planet Mercury is over the western horizon.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.

Uranus at Eastern Quadrature – 2021

   Tuesday January 26th the position of the planet Uranus with respect to the Earth and the Sun places this ringed planet at what is called eastern quadrature. Uranus is at a 90 degree angle from the Earth. Think first quarter Moon as that is a fair comparison of the relative positions of the Earth, the Sun, and Uranus – or any outer planet. At this position Uranus follows the Sun across the sky from east to west as the Earth is rotating, meaning that Uranus rises after the Sun and sets after the Sun.

   So, where is Uranus? Look over the southern horizon after sunset for the reddish star-like object – the planet Mars. A few degrees above Mars is the star Hamal in the constellation of Aries the Ram. About 4o down to the right from Mars is the outer ringed planet Uranus.

   With a 5.77 apparent magnitude Uranus is just bright enough to be seen with binoculars as perhaps a very small dot. However Uranus is at about the naked-eye limit of visibility (6th magnitude) so it would take extremely dark skies to see it without optical assistance. Compare the apparent magnitude of Uranus with that of Mars at 0.34 and the 2.00 apparent magnitude for the star Hamal.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


Also Follow me and other great resources at Feedspot.