91av

ACROSS

6 Below 0° (3-4)

7 US city, world headquarters of 3 down science (5,2)

9 Computing language; Beginner’s All-purpose Symbolic Instruction Code (5)

10 Component of atmospheric circulation (5,4)

11 The complete or partial obscuring of one celestial body by another (7)

13 In human anatomy, spaces surrounding the nasal cavity (7)

14 Term for the twinkling of stars (13)

18 In biology, relating to the body’s waste fluid (7)

19 Worker or machine that applies permanent mechanical fasteners (7)

21 In cosmology, the earliest stage of the big bang (6,3)

23 Female reproductive organ (5)

25 Sorosilicate mineral discovered in 1977 by Joe Ana Ruiz (7)

26 Bright green variety of beryl (7)

DOWN

1 Long-legged wading bird of the family Threskiornithidae (4)

2 Agaric mushroom aka a cortinar (6)

3 Property of systems in which behaviours are not explicable by analysis of component parts (10)

4 Private computer network run by a company or other organisation (8)

5 Columnar vortex occurring over a sea or lake (10)

6 In mathematics, a set contained within another set (6)

7 Astronomers’ term for a solar day on Mars (3)

8 Item of laboratory glassware developed by Emil Erlenmeyer (1-5)

12 CH₃CH(OH)COOH, an organic compound active in various biochemical processes (6,4)

13 An assembly of photovoltaic cells (5,5)

15 Biogeographic realm covering Greenland and most of North America (8)

16 Gerard ___ (1905–73), astronomer who gave his name to a belt of small bodies beyond the orbit of Neptune (6)

17 Studied using Röntgen radiation (1-5)

20 Colour at the end of the visible spectrum of light (6)

22 Mitochondrial ___, matrilineal most recent common ancestor of all living humans (3)

24 Protein belonging to a family of transmembrane and secreted metalloendopeptidases (4)