Meteorscatter
PREVIEW of 144 MHz-Activities for the upcomming METEOR-Showers

UPCOMING METEOR SHOWERS: AUGUST 2015

One of the most popular meteor showers, the Perseids, is coming. Although this shower has proven to be very dynamic in recent years, (especially in the 1990s, due to the perihelion passage of their parent comet, 109P/Swift-Tuttle in 1992, having orbital period of about 130 years) more recently the meteor activity was mostly concentrated around the “normal” peak, with ZHR around 100 hr-1, and even 2015 activity will basically follow this trend.

Recent IMO observations found that timing of “traditional” broad maximum varied between λsol=139°8 to 140°3, equivalent to 2015 August 13, 01h30m UT to 14h00m UT. Node is at λsol=140°0-140°1.
According to IMO, then the maximum in 2015 is expected to occur on August 13, most likely around 06h30m to 09h00m UT, with ZHR = 100 hr-1.

By the way there are some indications that the Perseids meteor rates in 2015 could be a bit higher than what detected in last few years.
According to Mikhail Maslov, (see here ), in 2015-2017 the Earth will encounter a part of Perseids stream perturbed and shifterd closer to Earth’s orbit by Jupiter gravitation. That will increase meteor rates especially in 2016, while in 2015, being the particles about 0.0045 AU closer to Earth than usual, ZHR should reach about 120 hr-1, with peak at the normal maximum (λsol=140°0).
Jeremie Vuabaillon’s theoretical modelling indicates that dust trail from the comet’s 1862 return should pass closest to the Earth (at about 0.00053 AU distance) at 18h39m UT on August 12th. Activity levels are uncertain, but whatever will happen they should persist for several hours around this potential peak.

Of course, some minor showers will also be active in August, κ-Cygnids and daylight γ-Leonids being the most significant.
Last but not least, don’t forget the great help given by Sporadic Meteors: their rates are very close to annual
maximum in August.



For Radio Observers, the (Theoretical) UT peaks for upcoming showers in August 2015 are as follows:

Perseids
Active: July 17 – August 24
Maximum: August 13, 06h30m UT (λsol= 140°0)
ZHR: HIGH (100 hr-1)

κ-Cignids
Active: August 03 – August 25
Maximum: August 18 (λsol= 145°)
ZHR: Low

γ-Leonids (Daytime shower)
Active: August 14 – September 12
Maximum: August 25 (λsol= 152°2)
ZHR: Low

(Source: IMO)




Some tips about Perseids

The Perseids Radiant is circumpolar (that means, is above horizon the entire day) for every observer northern of about 32°N latitude during shower activity.

For a Central Europe observer (say, in JN59 square and surroundings) the radiant is relatively low above horizon in late afternoon/early evening (15-18 UT) and rather high above horizon in early morning (03-06 UT). Optimal height of radiant above horizon for best radio efficiency can be found between 21 UT and 01 UT, and between 08 UT and 12 UT.

For the Central Europe observer mentioned above, the relative radiant position favors the radio paths in NE/SW direction in morning and early afternoon hours, and NW/SE direction during night hours. Best geometric efficiency direction Vs. Time around Perseids maximum can thus be summarized as follows:

Direction of radio path vs. Time for best efficiency (UT)

N/S: 8 - 11 and 23 – 02

NE/SW: 8 - 13

E/W: 10 – 13 and 20 – 23

NW/SE: 20 – 02


This calculation is valid for the center Europe observer as mentioned. Moving significantly away from that area will somewhat change the times for best efficiency, so this table should be used only for an approximate evaluation (although somehow valid for most Europe). Check your actual directions for best efficiency Vs. Time for your area, using tools like Virgo, OH5IY soft and so on. Please note that the above calculated efficiency applies better on Underdense trails ( that produce Pings), while Overdense trails ( that produce longer Bursts) are somewhat less dependent by geometry (radiant position with respect to direction of radio path).



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MMMonVHF MS Activity OVERVIEW (PAST SHOWERS)

As for past MS-Showers, the VHF-DX-Portal MMMonVHF will produce an up to date MS OVERVIEW concerning the next major Meteor Shower.


MMMonVHF since 2008, is archiving the ACTIVITY-OVERVIEWS related to the past major MS-Shower:

MS-SPRINT & PERSEIDS 2008:
OVERVIEW PDF-File & SQUARE-MAP

BCC & GEMINIDS 2008:
OVERVIEW PDF-File & SQUARE-MAP

MS-SPRINT & PERSEIDS 2009:
OVERVIEW PDF-File & SQUARE-MAP

BCC & GEMINIDS 2009:
OVERVIEW PDF-File & SQUARE-MAP

MS-SPRINT & PERSEIDS 2010:
OVERVIEW PDF-File & SQUARE-MAP

BCC & GEMINIDS 2010:
OVERVIEW PDF-File & SQUARE-MAP

MS-SPRINT & PERSEIDS 2011:
OVERVIEW PDF-File & SQUARE-MAP

BCC & GEMINIDS 2011:
OVERVIEW PDF-File & SQUARE-MAP




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