Archive

Archive for the ‘Mercury’ Category

11/10/2020 – Ephemeris – Mercury will reach it greatest separation from the Sun in the morning today

November 10, 2020 Comments off

This is Bob Moler with Ephemeris for Tuesday, November 10th. Today the Sun will be up for 9 hours and 45 minutes, setting at 5:19, and it will rise tomorrow at 7:35. The Moon, 2 days past last quarter, will rise at 2:42 tomorrow morning.

Mercury will reach its greatest western elongation from the Sun near noon today (17:00 UT). That means it was visible this morning before sunrise in the east. And will be visible again tomorrow morning. The next Mercury greatest elongation will be January 24th, next year. It will be a greatest eastern elongation, which will be visible in the western sky in the evening after sunset. So western elongations are seen in the east and eastern elongations are seen in the west. The “from the Sun” is usually omitted in astronomical lists of events, but implied. Sounds a bit confusing, but it makes weird sense. Mercury’s morning appearance will last about a week before it get too low to easily spot, below and left of Venus.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury, Venus, Moon tomorrow morning at 6:30 am

Mercury, Venus, Moon tomorrow morning November 11, 2020 at 6:30 am. The orange line is the ecliptic, the plane of the Earth’s orbit. It is the path of the Sun in the sky, The Moon and planets also stick close to that line. The Moon is a crescent, though that can’t be seen at this scale. Over the next week Venus and Mercury will slide downward along the ecliptic in relation to the stars, as will the Moon at greater speed. Created using Stellarium.

11/09/2020 – Ephemeris – Tiny Mercury makes an appearance in the morning sky

November 9, 2020 Comments off

This is Ephemeris for Monday, November 9th. Today the Sun will be up for 9 hours and 48 minutes, setting at 5:20, and it will rise tomorrow at 7:33. The Moon, 1 day past last quarter, will rise at 1:26 tomorrow morning.

The tiny planet Mercury is now visible in the morning twilight. It will reach its greatest separation from the Sun in the morning sky. Astronomers call it “greatest western elongation”. It’s west of the Sun, but we’ll see it in the eastern sky as it rises at 5:49 am in the east-southeast. That’s an hour and 44 minutes before the Sun. By 6:15 or 6:30 am, it should be high enough to spot. That is if it’s clear, an iffy prospect this time of year. It will start to move back to the Sun and actually brighten retaining its best visibility for the next 7 days or so. Mercury has a very elliptical orbit of the Sun. During our two good seasons to view the planet, spring evenings and autumn mornings Mercury is closest to the Sun. Mercury is best seen in the southern hemisphere when its autumn morning appearances and spring evening appearances are seen when Mercury is farthest from the Sun.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury and Venus in the morning at 6:30 am

Mercury and Venus in the morning at 6:30 am. Created using Stellarium.

 

02/25/2020 – Ephemeris – Mercury at inferior conjunction with the Sun today

February 25, 2020 Comments off

Ephemeris for Fat Tuesday, February 25th. Today the Sun will be up for 10 hours and 56 minutes, setting at 6:24, and it will rise tomorrow at 7:26. The Moon, 2 days past new, will set at 8:27 this evening.

A bit more than two weeks ago Mercury was visible in the evening twilight at its greatest elongation from the Sun, then at 8:37 this evening it will pass between the Earth and the Sun and enter the morning sky. The event is called an inferior conjunction. That’s not a dig on the quality of the event. Indeed an inferior conjunctions are more important and can produce a transit of the planet across the Sun. A rare and formerly important event when we were trying to determine the distance to the Sun. In astronomy an inferior planet is one that orbits the Sun inside the Earth’s orbit. A superior planet orbits the Sun farther than the Earth. It’s not a sign of quality. The best time to spot Mercury in the morning is in August to October, so we’ll miss Mercury this time.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury at inferior conjunction

Mercury about 7 hours before inferior conjunction February 25, 2020 near local solar noon. The last inferior conjunction of Mercury on November 11, 2019 Mercury passed across the Sun’s disk in a transit. The red ellipse is Mercury’s orbit as seen From the Earth. It’s orbit is tilted about 7 degrees from the Earth’s orbit, so transits are fairly rare events. Created using Stellarium.

11/28/2019 – Ephemeris – This is the best time to spot Mercury in the morning

November 28, 2019 Comments off

Ephemeris for Thanksgiving Day, Thursday, November 28th. Today the Sun will be up for 9 hours and 8 minutes, setting at 5:05, and it will rise tomorrow at 7:57. The Moon, 2 days past new, will set at 6:59 this evening.

The planet Mercury is at its greatest western elongation from the Sun this morning. Being west of the Sun it rises first. It being a planet inside the Earth’s orbit it appears to swing from the east side to the west side of the Sun, from the evening to the morning side of the Sun. It never appears outside of twilight around here. For the next week it will be going away from us, and becoming more illuminated by the Sun from our perspective, and actually is getting brighter. Then it will seem to fall back, actually moving around and behind the Sun. This evening the thin sliver of the Moon will appear near brilliant Venus. The best time to look is around an hour after sunset, which is about 6 p.m. Venus will set at 6:43 p.m.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury for the next week

Mercury in the morning, about an hour before sunrise (7 a.m. here) for the next week. The aspect of its orbit changes for two reasons, sunrise time is advancing a bit, and the Earth is changing its position with respect to Mercury and its orbit, and Mercury too is moving. Create using Stellarium and GIMP.

06-18-2019 – Ephemeris – Mercury and Mars will be seen together tonight

June 18, 2019 Comments off

Ephemeris for Tuesday, June 18th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:56. The Moon, 1 day past full, will rise at 10:49 this evening.

This evening the Planets Mercury and Mars will appear less than a moon-width apart in the evening twilight. Mercury, the brighter of the two, by a factor of 4 times, will be visible first, at about 10:15 p.m. very low in the west-northwest. Mars will be immediately below it by less than the width of the Moon. At that time they will be a bit less than the width of your fist held at arm’s length above the horizon. Binoculars are the best way to spot them. Mercury will continue to move eastward in the sky away from Mars. Until after it reaches its greatest separation from the Sun on the 23rd. It will then head back and pass at a much greater distance below Mars on July 5th. This is the best chance to spot Mercury in the evening sky this year.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury-Mars Conjunction

Mercury and Mars this evening at 10:30 p.m., June 18, 2019. Created using Stellarium.

10/25/2018 – Ephemeris – Europe and Japan launch a joint mission to Mercury

October 25, 2018 Comments off

Ephemeris for Thursday, October 25th. The Sun will rise at 8:11. It’ll be up for 10 hours and 30 minutes, setting at 6:41. The Moon, 1 day past full, will rise at 7:44 this evening.

A joint mission to Mercury by the Europeans and the Japanese called BepiColumbo was launched late Friday night October 19th our time (EDT), 20th (UT). It will take 7 years to be able to drop into orbit of the innermost planet to make only the second spacecraft to do so. To drop into Mercury’s orbit from the Earth’s orbit the spacecraft will need to lose a whole lot of velocity. The trip there will entail one flyby of the Earth, two of Venus, and six of Mercury itself. Planetary flybys have been used since the 1970s to use a planet’s velocity to add to or subtract from a spacecraft’s velocity, depending on how it approaches the planet. If crossing in front of a planet some velocity is subtracted from the spacecraft, allowing it to drop closer to the Sun. If coming up from behind the spacecraft gets to add to its velocity relative to the Sun.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Orbits
Animation of BepiColombo’s trajectory from 20 October 2018 to 2 November 2025. Earth’s orbit Blue, Cyan Venus, Green Mercury, Purple BepiColumbo.
BepiColumbo
BepiColumbo spacecraft separates into two acitve satellites at Mercury. ESA’s MPO, Mercury Planetary Orbiter; and JAXA’s MMO, Mercury Magnetospheric Orbiter. Credit DLR/ESA

08/23/2018 – Ephemeris – Mercury’s morning appearance

August 23, 2018 Comments off

Ephemeris for Thursday, August 23rd. The Sun rises at 6:54. It’ll be up for 13 hours and 40 minutes, setting at 8:35. The Moon, 3 days before full, will set at 4:56 tomorrow morning. | The tiny and elusive planet Mercury is making an appearance in the morning sky now. On Sunday afternoon our time Mercury will at its greatest elongation or separation west of the Sun. So Sunday or Monday mornings are the very best time to spot it. Look to the east-northeast at a low horizon to spot it. It should be visible from about 6 a.m. to about 6:40 a.m. before twilight swamps it. There are no stars of comparable brightness near it. It’s seen against the dim stars of Cancer the crab. The bright stars Pollux and Castor of Gemini will appear a ways above it. It should be visible from now through next week. Today is the day of the mini-Moon, its smallest of the month at 252 thousand miles (406 thousand km) away.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The motion of Mercury

The motion of Mercury from August 23 to September 1, 2018. For each day the magnitude of Mercury is given. Note that gets brighter over the period. That is the magnitudes get more negative. The is due to Mercury’s increasing phase, getting fuller as it moves around the Sun. Created using Cartes du Ciel (Sky Charts).

Categories: Ephemeris Program, Mercury

03/28/2017 – Ephemeris – Mercury is visible in the evening sky now

March 28, 2017 Comments off

Ephemeris for Tuesday, March 28th. The Sun will rise at 7:30. It’ll be up for 12 hours and 35 minutes, setting at 8:05. The Moon, 1 day past new, will set at 8:56 this evening.

Mercury is in the evening sky now for it’s spring appearance. Mercury is best seen when it’s near its farthest from the Sun on spring evenings and autumn mornings. Mercury will reach its greatest elongation east of the Sun this coming Saturday with a 19 degree angle of separation from the Sun. This tiny planet is brighter before eastern elongating than after it. I find that the optimal time to look for Mercury is about 45 minutes after sunset. That makes it about 8:50 p.m. At that time Mercury will be low in the west only 9 degrees above the horizon. That’s a bit less than the width of a fist held at arm’s length above the lake or sea horizon, or the base of distant trees that are on your level. Mercury will be visible for about a week or so.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury near the western horizon at 8:50 p.m. or 45 minutes after sunset. Also shown is its orbit as it appears tonight. The Moon and Uranus are not actually visible in the twilight glare. Mars will be visible a bit later. The Moon will appear between Mercury and Mars tomorrow night. Created using Stellarium.

09/12/2016 – Ephemeris – Mercury passes inferior conjunction with the Sun today

September 12, 2016 Comments off

Ephemeris for Monday, September 12th. The Sun will rise at 7:18. It’ll be up for 12 hours and 39 minutes, setting at 7:58. The Moon, 3 days past first quarter, will set at 3:34 tomorrow morning.

Today the Planet Mercury will pass inferior conjunction, that is move between the Earth and the Sun. Unlike last inferior conjunction, when it passed directly in front of the Sun on May 9th. This time it will pass below the Sun. The term inferior means it is between the Earth and the Sun. A superior conjunction is when Mercury passes the back side of the Sun. Mercury will be moving into the morning side of the sky, and toward the end of the month it will be much easier to spot than it was last month when it was low in the west. On autumn mornings the ecliptic, the path of the Sun and planets, sticks up, close to vertical, while in the evenings it lies close to the horizon, which is also why Venus sets so soon after the Sun now.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Greatest Eastern Elongation of Mercury

Mercury last August 16 at greatest eastern elongation. Note how low Mercury is to the horizon at sunset. Created using Cartes du Ciel (Sky Charts).

Note in the charts above and below the line passing through the Sun, and the one the planets hang around is the ecliptic, the projection of the Earth’s orbit on the celestial sphere.  The grid line running through the west compass point at the horizon is the celestial equator.  I’m allowing us to see below the horizon.  As planets rise, move across the sky and set they will appear to move parallel to the celestial equator.

Greatest Western Elongation of Mercury

Mercury this coming September 28 at greatest western elongation. Note how high Mercury is to the horizon at sunrise. Created using Cartes du Ciel (Sky Charts).

Note too that Mercury appears farther from the Sun on August 16th than at September 28th.  And it is.  On August 16th Mercury appears 27.4 degrees from the Sun.  On September 28th, it’s only 17.8 degrees.  That’s a big advantage for observers in the southern hemisphere.  The best times to see an eastern elongation of Mercury is on winter and spring evenings, and the best times to see a western elongation of Mercury is on summer and autumn mornings.  Since the seasons are reversed from the northern hemisphere to the southern hemisphere.  Our not so good August 16th elongation of Mercury was a really good one for folks south of the equator.  We’ll return the favor September 28th.  But the best southern hemisphere greatest elongations are always greater in the separation of Mercury from the Sun  than northern ones because Mercury has a markedly elliptical orbit.

 

 

Some views of the festivities at the Sleeping Bear Dunes National Lakeshore Dune Climb for the transit of Mercury earlier today

May 9, 2016 Comments off

Transiting Mercury

Mercury and some sunspots at 8:30 a.m. through my telescope. Thought I’d take a shot before we had visitors. C8 Cassigrainian focus, ISO 100, 1/100 second.

Viewing thru the Dobinator

Checking the transit via the “Dobinator” through the Grand Traverse Astronomical Society’s (GTAS) 25 inch Dobsonian stopped down with an 8″ solar filter.

My C8

Viewing the transit through my Celestron C8.

Viewing the transit

Kids viewing the transit through the society’s Lunt hydrogen alpha solar telescope.

Emmett's Dobsonian

Youngster viewing the transit through Emmett Holmes’ 13″ homemade Dobsonian telescope and Poncet tracking mount.

Credit:  Bob Moler