Here comes Jupiter! NASA's robotic spacecraft Juno is continuing on its 53-day, highly-elongated orbits around our Solar System's largest planet. The featured video is from perijove 11, the eleventh time Juno has passed near Jupiter since it arrived in mid-2016. This time-lapse, color-enhanced movie covers about four hours and morphs between 36 JunoCam images. The video begins with Jupiter rising as Juno approaches from the north. As Juno reaches its closest view -- from about 3,500 kilometers over Jupiter's cloud tops -- the spacecraft captures the great planet in tremendous detail. Juno passes light zones and dark belt of clouds that circle the planet, as well as numerous swirling circular storms, many of which are larger than hurricanes on Earth. After the perijove, Jupiter recedes into the distance, now displaying the unusual clouds that appear over Jupiter's south. To get desired science data, Juno swoops so close to Jupiter that its instruments may soon fail due to exposure to high levels of radiation. Because of this, in part, the Juno mission is currently schedule to conclude in mid-2018, at perijove 14, when the spacecraft will be directed to dive into Jupiter's atmosphere and melt. via NASA http://ift.tt/2FvQzTt
February 22, 2018
Not all roses are red of course, but they can still be very pretty. Likewise, the beautiful Rosette Nebula and other star forming regions are often shown in astronomical images with a predominately red hue, in part because the dominant emission in the nebula is from hydrogen atoms. Hydrogen's strongest optical emission line, known as H-alpha, is in the red region of the spectrum, but the beauty of an emission nebula need not be appreciated in red light alone. Other atoms in the nebula are also excited by energetic starlight and produce narrow emission lines as well. In this gorgeous view of the Rosette Nebula, narrowband images are combined to show emission from sulfur atoms in red, hydrogen in blue, and oxygen in green. In fact, the scheme of mapping these narrow atomic emission lines into broader colors is adopted in many Hubble images of stellar nurseries. The image spans about 100 light-years in the constellation Monoceros, at the 3,000 light-year estimated distance of the Rosette Nebula. To make the Rosette red, just follow this link or slide your cursor over the image. via NASA http://ift.tt/2EV0eoC
February 20, 2018
What's happened to top of the Sun? Last week, parts of Earth's southern hemisphere were treated to a partial solar eclipse, where the Moon blocks out part of the Sun. The featured image was taken toward the end of the eclipse from the coast of Uruguay overlooking Argentina's Buenos Aires. Light-house adorned Farallón Island is seen in the foreground, and a plane is visible just to the left of the Sun. The image is actually a digital combination of two consecutive exposures taken with the same camera using the same settings -- one taken of the landscape and another of the background Sun. The next solar eclipse visible on Earth will be another partial eclipse occurring in mid-July and visible from parts of southern Australia including Tasmania. via NASA http://ift.tt/2C73dJH
February 18, 2018
How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? To understand details better, astrophysicists upgraded the famous Illustris Simulation into IllustrisTNG -- now the most sophisticated computer model of how galaxies evolved in our universe. Specifically, this featured video tracks magnetic fields from the early universe (redshift 5) until today (redshift 0). Here blue represents relatively weak magnetic fields, while white depicts strong. These B fields are closely matched with galaxies and galaxy clusters. As the simulation begins, a virtual camera circles the virtual IllustrisTNG universe showing a young region -- 30-million light years across -- to be quite filamentary. Gravity causes galaxies to form and merge as the universe expands and evolves. At the end, the simulated IllustrisTNG universe is a good statistical match to our present real universe, although some interesting differences arise -- for example a discrepancy involving the power in radio waves emitted by rapidly moving charged particles. via NASA http://ift.tt/2CuxNZz
February 17, 2018
Stars can make waves in the Orion Nebula's sea of gas and dust. This esthetic close-up of cosmic clouds and stellar winds features LL Orionis, interacting with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged Sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed. The small, arcing, graceful structure just above and left of center is LL Ori's cosmic bow shock, measuring about half a light-year across. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the upper left corner of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. This beautiful painting-like photograph is part of a large mosaic view of the complex stellar nursery in Orion, filled with a myriad of fluid shapes associated with star formation. via NASA http://ift.tt/2F9mp8d
February 11, 2018
What's that heading for the Pleiades star cluster? It appears to be Comet C/2016 R2 (PanSTARRS), but here, appearances are deceiving. On the right and far in the background, the famous Pleiades star cluster is dominated by blue light from massive young stars. On the left and visiting the inner Solar System is Comet PanSTARRS, a tumbling block of ice from the outer Solar System that currently sports a long ion tail dominated by blue light from an unusually high abundance of ionized carbon monoxide. Comet PanSTARRS is actually moving toward the top of the image, and its ion tail points away from the Sun but is affected by a complex solar wind of particles streaming out from the Sun. Visible through a small telescope, the comet is fading as it recedes from the Earth, even though it reaches its closest point to the Sun in early May. via NASA http://ift.tt/2Ch24uQ
What's happened to the setting Sun? An eclipse! In early 2009, the Moon eclipsed part of the Sun as visible from parts of Africa, Australia, and Asia. In particular the featured image, taken from the Mall of Asia seawall, caught a partially eclipsed Sun setting over Manila Bay in the Philippines. Piers are visible in silhouette in the foreground. Eclipse chasers and well placed sky enthusiasts captured many other interesting and artistic images of the year's only annular solar eclipse, including movies, eclipse shadow arrays, and rings of fire. On Thursday parts of the Sun again will become briefly blocked by the Moon, again visible to some as a partial eclipse of the Sun. Thursday's eclipse, however, will only be visible from parts of southern South America and Antarctica. via NASA http://ift.tt/2Ei6EKV
February 10, 2018
Don't panic. It's just a spacesuited mannequin named Starman. As the sunlit crescent of planet Earth recedes in the background, Starman is comfortably seated at the wheel of a Tesla Roadster in this final image of the payload launched by a Falcon Heavy rocket on February 6. Internationally designated 2018-017A, roadster and Starman are headed for space beyond the orbit of Mars. The successful Falcon Heavy rocket has now become the most powerful rocket in operation and the roadster one of four electric cars launched from planet Earth. The other three were launched to the Moon by historically more powerful (but not reusable) Saturn V rockets. Still, Starman's roadster is probably the only one that would be considered street legal. via NASA http://ift.tt/2C9n06N
February 9, 2018
This digitally processed and composited picture creatively compares two famous eclipses in one; the total lunar eclipse (left) of January 31, and the total solar eclipse of August 21, 2017. The Moon appears near mid-totality in both the back-to-back total eclipses. In the lunar eclipse, its surface remains faintly illuminated in Earth's dark reddened shadow. But in the solar eclipse the Moon is in silhouette against the Sun's bright disk, where the otherwise dark lunar surface is just visible due to earthshine. Also seen in the lunar-aligned image pair are faint stars in the night sky surrounding the eclipsed Moon. Stunning details of prominences and coronal streamers surround the eclipsed Sun. The total phase of the Great American Eclipse of August 21 lasted about 2 minutes or less for locations along the Moon's shadow path. From planet Earth's night side, totality for the Super Blue Blood Moon of January 31 lasted well over an hour. via NASA http://ift.tt/2H0ceDv
February 8, 2018
On January 31, a leisurely lunar eclipse was enjoyed from all over the night side of planet Earth, the first of three consecutive total eclipses of the Moon. This dramatic time-lapse image followed the celestial performance for over three hours in a combined series of exposures from Hebei Province in Northern China. Fixed to a tripod, the camera records the Full Moon sliding through a clear night sky. Too bright just before and after the eclipse, the Moon's bow tie-shaped trail grows narrow and red during the darker total eclipse phase that lasted an hour and 16 minutes. In the distant background are the colorful trails of stars in concentric arcs above and below the celestial equator. via NASA http://ift.tt/2nMd7aI
February 7, 2018
Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. In this Hubble Space Telescope close-up, the galaxy's magnificent spiral arms feature dark obscuring dust lanes, bright bluish clusters of massive young stars, and the telltale reddish glow of active star forming regions. The bright yellowish central regions harbor populations of older, cooler stars. Like the Milky Way, a supermassive black hole lies at the core of of spiral galaxy NGC 7331. via NASA http://ift.tt/2nSqeqm
February 6, 2018
What's happening to galaxy NGC 474? The multiple layers of emission appear strangely complex and unexpected given the relatively featureless appearance of the elliptical galaxy in less deep images. The cause of the shells is currently unknown, but possibly tidal tails related to debris left over from absorbing numerous small galaxies in the past billion years. Alternatively the shells may be like ripples in a pond, where the ongoing collision with the spiral galaxy just above NGC 474 is causing density waves to ripple through the galactic giant. Regardless of the actual cause, the featured image dramatically highlights the increasing consensus that at least some elliptical galaxies have formed in the recent past, and that the outer halos of most large galaxies are not really smooth but have complexities induced by frequent interactions with -- and accretions of -- smaller nearby galaxies. The halo of our own Milky Way Galaxy is one example of such unexpected complexity. NGC 474 spans about 250,000 light years and lies about 100 million light years distant toward the constellation of the Fish (Pisces). via NASA http://ift.tt/2E2NEQx
February 4, 2018
It's the bubble versus the cloud. NGC 7635, the Bubble Nebula, is being pushed out by the stellar wind of massive star BD+602522, visible in blue toward the right, inside the nebula. Next door, though, lives a giant molecular cloud, visible to the far right in red. At this place in space, an irresistible force meets an immovable object in an interesting way. The cloud is able to contain the expansion of the bubble gas, but gets blasted by the hot radiation from the bubble's central star. The radiation heats up dense regions of the molecular cloud causing it to glow. The Bubble Nebula, pictured here is about 10 light-years across and part of a much larger complex of stars and shells. The Bubble Nebula can be seen with a small telescope towards the constellation of the Queen of Aethiopia (Cassiopeia). via NASA http://ift.tt/2nDAinx
|Azden AZ-61 6m FM HT|
This is an article in a series regarding the vintage Azden AZ-61 6m FM Transceiver.
The Azden AZ-61 comes with 50 Ohm BNC antenna connector and a rubber duck style antenna. An excellent way to get more out of this radio is to upgrade the antenna. There are several 6m BNC antennas on the market or you could build your own.
KC0BIN (Rob Johnson) contacted me recently to share that he has had very good results with the Diamond RH-205 BNC antenna on his Azden AZ-61. The antenna telescopes out to about 52.75 inches, and this length coincidentally resonates well on the FM portion of the 6M band. Thank you Rob for this helpful tip.
Good DX and 73, NJ2X
Other related articles on NJ2X.COM:
Azden AZ-61 6m FM HT - Tip #1 - How to program the radio
Azden AZ-61 6m FM HT - Tip #2 - disabling "the beep"
Azden AZ-61 6m FM HT - Tip #3 - 1993 review article
Azden AZ-61 6m FM HT - Tip #4 - rebuilding the battery pack
Azden AZ-61 6m FM HT - Tip #5 - how to reset the radio
Azden AZ-61 6m FM HT - Tip #6 - Automatic Power-Off
Azden AZ-61 6m FM HT - Tip #7 - VFO Mode
Azden AZ-61 6m FM HT - Tip #8 - Frequency Step
Azden AZ-61 6m FM HT - Tip #9 - Scanning
Azden AZ-61 6m FM HT - Tip #10 - Dual Watch
Azden AZ-61 6m FM HT - Tip #11 - Battery Saver
Azden AZ-61 6m FM HT - Tip #12 - Optional Accessories
Azden AZ-61 6m FM HT - Tip #13 - Specifications
Azden AZ-61 6m FM HT - Tip #12 - Optional Accessories
Azden AZ-61 6m FM HT - Tip #13 - Specifications
© Michael W. Maher and NJ2X.COM, 2017. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Michael W. Maher and NJ2X.COM with appropriate and specific direction to the original content.
February 2, 2018
This atmospheric picture of a distant horizon looks toward the tall Trisul peaks of India's snowy Himalayan mountains. Taken from a remote location on January 31, brightest star Sirius shines at the upper right. The red Moon rising is gliding through Earth's shadow during the evening's much anticipated total lunar eclipse. Enjoyed across the planet's night side, the eclipse was the first of two total lunar eclipses in 2018, kicking off a good year for moonwatchers. But this was a rare treat. The eclipsed Moon also loomed large near perigee, the closest point in its orbit, during the second Full Moon of the month, also known as a Blue Moon. For the July 27, 2018 total lunar eclipse, the Full Moon will be very near apogee.