Astronomy Section

The NSS astronomy section

Astronomy section activities fall into two categories: meetings which usually including a talk by a speaker, and observing, both at public and member-only sessions at the Cawthron Atkinson Observatory (at Clifton Terrace School), at home observatories and backyards, and at dark sky locations in the district including  the recently designated Wai-Iti Dark Sky Park.

Membership fee to join the section is an $20 additional to membership fee to join the Nelson Science Society itself. Please deposit the $20 fees to ANZ account number 11-7400-0445502-14 with SUBS21 in the reference and your surname in the particulars, and send an email to

Members enjoy the benefits of free access to the observatory and can also borrow one of the two library loan telescopes (deposit required for loan).

Currently the Astronomy Section is seeking to fill secretary and membership secretary committee positions.

If you are interested to become a member of the astronomy section or to assist with the organisation please contact the convenor, Hamish Barker on 0226760897 or email

6th May 2021 Meeting: David Wing.  Meteorology of Mars

David will present on the state of knowledge on the meteorology of mars, including some of his own research and modelling which has influenced selection of landing sites for previous NASA Mars landers and rovers.

7:30pm Thursday 6th May 2021, Milton Room, Cawthron Institute.


Public nights at the observatory start after daylight savings ends (we don’t generally open during daylight savings because twilight goes too late.). All welcome!

The first public night for 2021 is currently scheduled for Friday 9th of April (that’s the Friday after Easter).

Public nights are held on each clear sky (or at least partly clear) Friday evening until the end of September, 7.30pm to 9.30pm, Cawthron Atkinson Observatory, Clifton Terrace School, Atawhai, Nelson.

Come along and observe the universe through our C14 telescope and our other, portable, telescopes. For the next few months, the only planets other than the moon which will observable in the evening sky will be Mars (and that will be out of view soon anyway), and then saturn will start to rise from about july. When the moon isn’t in the sky, there are a plenty of interesting nebulae (gas and dust clouds between the stars), star clusters and (on when the moon is not there, as they are faint and hard to see) galaxies to see.

The astronomy section has a couple of library telescopes are available for 1 week renewable loan with deposit and a short training session.

Public night admission charges to support the running costs of the observatory are (cash only) $5 per person, $15 families. Astronomy Section members free admission.

Private observatory group sessions for can also be arranged. For further information, please contact Hamish Barker, Astronomy Section Convenor, on 0226760897.

Wai-iti Dark Sky Park

Congratulations to Ralph Bradley and the  ‘Top of the South Dark Sky’ committee and its online identity ‘Dark Skies Tasman’ for their five years of hard work and their success in getting the Wai-iti Recreation Reserve and Tunnicliff Forest designated New Zealand’s first ‘Dark Sky Park’.

The park covers 135 hectares of Tasman District Council (TDC) land, located 4km south of Wakefield, and accompanies existing International Dark Sky Association (IDA)-recognised Dark Sky Reserves and Sanctuaries in Aoraki-Mackenzie, Stewart Island/Rakiura and Aotea/Great Barrier.

Dark Sky Week from 5th to 12th april, is planned to include an event at the park, most likely on the weekend, although details are yet to be finalised.

Please register for the star party events on the Dark Skies Tasman website.

Lunar Eclipse (“blood moon”) May 26th 2021

A total lunar eclipse will happen on the night of Wednesday May 26th 2021. The whole eclipse will be visible (clouds permitting!), starting at 8:47pm and finishing at 1:49am. As yet we don’t have an event organised, but hopefully we can get a bunch of telescopes set up somewhere for a fun event. Watch this space.

      Up coming events:

 Training of Night sky guides:
The newly formed Aotearoa Astrotourism Academy will be offering its first course for the
training of night sky guides in Tekapo 10-12 September.
Details are on their website and in this file.

 Astronomy Talks
Bill Rea will be presenting presenting on gravitational waves astronomy and dark matter    1. Gravitational Wave Astronomy:
This would cover what gravitational waves are and how they are
generated. Then move to how LIGO and Virgo work, those are the
existing gravitational wave observatories. Rounding the talk off with
some of the events detected and what we’ve learned from them. The talk
would not cover either the bar gravitational wave detectors or the
pulsar timing arrays.
7:30pm Thursday 1st July 2021, Milton Room, Cawthron Institute.

2. Dark Matter — The Death of Modified Gravity
This talk would review three lines of evidence (galaxy cluster
velocity dispersion, galaxy rotation curves, and gravitational
lensing) which lead astronomers believe that there is a substantial
amount of dark matter in the universe. I would then give a brief recap
of talk 1 for anyone who missed it. Then cover GW170817 and associated
other observations and discuss how this rules out several entire
classes of modified gravity theories leaving modified gravity with
almost no viable options.
7:30pm Thursday 5th August, Milton Room, Cawthron Institute.

RASNZ Conference 2021:

The RASNZ Conference for 2021 will be held in Wellington during the weekend of Friday 9th to Sunday 11th July 2021.
The RASNZ website has Conference information at  Or see the flyers and other info here.
The deadline for the Murray Geddes and Dark Sky Bright Star awards is fast approaching. The deadlines are the 11th May 2021. To read more click here. If you wish to nominate someone for either award, please send me the completed nomination form click here

RASNZ Keeping-in-touch latest newsletter cab be found here.